diff --git a/api/v1/serializers.py b/api/v1/serializers.py
index 4b26877e..96630f50 100644
--- a/api/v1/serializers.py
+++ b/api/v1/serializers.py
@@ -74,7 +74,7 @@ class GalleryImageSerializer(GalleryImageCreateSerializer):
     img = ImageObjectSerializer()
 
 
-class MaterialSerializer(serializers.ModelSerializer):
+class MaterialCreateSerializer(serializers.ModelSerializer):
 
     class Meta:
         model = Material
@@ -89,12 +89,15 @@ class MaterialSerializer(serializers.ModelSerializer):
 
         read_only_fields = (
             'id',
-            'cover',
             'created_at',
             'update_at',
         )
 
 
+class MaterialSerializer(MaterialCreateSerializer):
+    cover = ImageObjectSerializer()
+
+
 class LikeSerializer(serializers.ModelSerializer):
 
     class Meta:
@@ -127,9 +130,7 @@ class CategorySerializer(serializers.ModelSerializer):
         )
 
 
-class CourseSerializer(serializers.ModelSerializer):
-    cover = ImageObjectSerializer()
-    gallery = GallerySerializer()
+class CourseCreateSerializer(serializers.ModelSerializer):
 
     class Meta:
         model = Course
@@ -164,15 +165,14 @@ class CourseSerializer(serializers.ModelSerializer):
         )
 
 
-class CourseRetrieveSerializer(CourseSerializer):
+class CourseSerializer(CourseCreateSerializer):
     category = CategorySerializer()
     materials = MaterialSerializer(many=True)
     cover = ImageObjectSerializer()
     gallery = GallerySerializer()
 
 
-class LessonSerializer(serializers.ModelSerializer):
-    cover = ImageObjectSerializer()
+class LessonCreateSerializer(serializers.ModelSerializer):
 
     class Meta:
         model = Lesson
@@ -189,15 +189,18 @@ class LessonSerializer(serializers.ModelSerializer):
 
         read_only_fields = (
             'id',
-            'cover',
             'content',
             'created_at',
             'update_at',
         )
 
 
-class ImageSerializer(serializers.ModelSerializer):
-    img = ImageObjectSerializer()
+class LessonSerializer(LessonCreateSerializer):
+    course = CourseSerializer()
+    cover = ImageObjectSerializer()
+
+
+class ImageCreateSerializer(serializers.ModelSerializer):
 
     class Meta:
         model = Image
@@ -219,7 +222,13 @@ class ImageSerializer(serializers.ModelSerializer):
         )
 
 
-class TextSerializer(serializers.ModelSerializer):
+class ImageSerializer(ImageCreateSerializer):
+    course = CourseSerializer()
+    lesson = LessonSerializer()
+    img = ImageObjectSerializer()
+
+
+class TextCreateSerializer(serializers.ModelSerializer):
 
     class Meta:
         model = Text
@@ -240,8 +249,12 @@ class TextSerializer(serializers.ModelSerializer):
         )
 
 
-class ImageTextSerializer(serializers.ModelSerializer):
-    img = ImageObjectSerializer()
+class TextSerializer(TextCreateSerializer):
+    course = CourseSerializer()
+    lesson = LessonSerializer()
+
+
+class ImageTextCreateSerializer(serializers.ModelSerializer):
 
     class Meta:
         model = ImageText
@@ -264,7 +277,13 @@ class ImageTextSerializer(serializers.ModelSerializer):
         )
 
 
-class VideoSerializer(serializers.ModelSerializer):
+class ImageTextSerializer(ImageTextCreateSerializer):
+    course = CourseSerializer()
+    lesson = LessonSerializer()
+    img = ImageObjectSerializer()
+
+
+class VideoCreateSerializer(serializers.ModelSerializer):
 
     class Meta:
         model = Video
@@ -285,6 +304,11 @@ class VideoSerializer(serializers.ModelSerializer):
         )
 
 
+class VideoSerializer(VideoCreateSerializer):
+    course = CourseSerializer()
+    lesson = LessonSerializer()
+
+
 class UserSerializer(serializers.ModelSerializer):
 
     class Meta:
diff --git a/api/v1/views.py b/api/v1/views.py
index af0b0e4a..db87e030 100644
--- a/api/v1/views.py
+++ b/api/v1/views.py
@@ -7,13 +7,17 @@ from rest_framework.response import Response
 
 from . import ExtendedModelViewSet
 from .serializers import (
-    CategorySerializer, CourseSerializer,
-    MaterialSerializer, LikeSerializer,
-    ImageSerializer, TextSerializer,
-    ImageTextSerializer, VideoSerializer,
-    GallerySerializer, GalleryImageSerializer, GalleryImageCreateSerializer,
+    CategorySerializer, LikeSerializer,
+    CourseSerializer, CourseCreateSerializer,
+    MaterialSerializer, MaterialCreateSerializer,
+    ImageSerializer, ImageCreateSerializer,
+    TextSerializer, TextCreateSerializer,
+    ImageTextSerializer, ImageTextCreateSerializer,
+    VideoSerializer, VideoCreateSerializer,
+    GallerySerializer,
+    GalleryImageSerializer, GalleryImageCreateSerializer,
     UserSerializer, UserPhotoSerializer,
-    LessonSerializer, CourseRetrieveSerializer,
+    LessonSerializer, LessonCreateSerializer,
     ImageObjectSerializer,
 )
 from .permissions import IsAdmin, IsAdminOrIsSelf, IsAuthorOrAdmin, IsAuthorObjectOrAdmin
@@ -35,7 +39,11 @@ class ImageObjectViewSet(ExtendedModelViewSet):
 
 class MaterialViewSet(ExtendedModelViewSet):
     queryset = Material.objects.all()
-    serializer_class = MaterialSerializer
+    serializer_class = MaterialCreateSerializer
+    serializer_class_map = {
+        'list': MaterialSerializer,
+        'retrieve': MaterialSerializer,
+    }
     search_fields = ('title', 'short_description',)
     ordering_fields = ('title', 'created_at', 'update_at',)
     # permission_classes = (IsAdmin,)
@@ -63,10 +71,10 @@ class CourseViewSet(ExtendedModelViewSet):
     ).prefetch_related(
         'likes', 'materials', 'content',
     ).all()
-    serializer_class = CourseSerializer
+    serializer_class = CourseCreateSerializer
     serializer_class_map = {
-        'list': CourseRetrieveSerializer,
-        'retrieve': CourseRetrieveSerializer,
+        'list': CourseSerializer,
+        'retrieve': CourseSerializer,
     }
     filter_fields = ('category', 'status', 'is_infinite', 'is_featured',)
     search_fields = ('author__email', 'title', 'category__title',)
@@ -82,7 +90,11 @@ class LessonViewSet(ExtendedModelViewSet):
     queryset = Lesson.objects.select_related(
         'course', 'cover'
     ).prefetch_related('content').all()
-    serializer_class = LessonSerializer
+    serializer_class = LessonCreateSerializer
+    serializer_class_map = {
+        'list': LessonSerializer,
+        'retrieve': LessonSerializer,
+    }
     filter_fields = ('course',)
     search_fields = ('title', 'short_description',)
     ordering_fields = ('title', 'created_at', 'update_at',)
@@ -97,7 +109,11 @@ class ImageViewSet(ExtendedModelViewSet):
     queryset = Image.objects.select_related(
         'course', 'lesson', 'img',
     ).all()
-    serializer_class = ImageSerializer
+    serializer_class = ImageCreateSerializer
+    serializer_class_map = {
+        'list': ImageSerializer,
+        'retrieve': ImageSerializer,
+    }
     search_fields = ('title',)
     ordering_fields = ('title', 'created_at', 'update_at', 'position',)
     # permission_classes = (IsAuthorOrAdmin,)
@@ -110,7 +126,11 @@ class TextViewSet(ExtendedModelViewSet):
     queryset = Text.objects.select_related(
         'course', 'lesson'
     ).all()
-    serializer_class = TextSerializer
+    serializer_class = TextCreateSerializer
+    serializer_class_map = {
+        'list': TextSerializer,
+        'retrieve': TextSerializer,
+    }
     search_fields = ('title',)
     ordering_fields = ('title', 'created_at', 'update_at', 'position',)
     # permission_classes = (IsAuthorOrAdmin,)
@@ -123,7 +143,11 @@ class ImageTextViewSet(ExtendedModelViewSet):
     queryset = ImageText.objects.select_related(
         'course', 'lesson', 'img'
     ).all()
-    serializer_class = ImageTextSerializer
+    serializer_class = ImageTextCreateSerializer
+    serializer_class_map = {
+        'list': ImageTextSerializer,
+        'retrieve': ImageTextSerializer,
+    }
     search_fields = ('title',)
     ordering_fields = ('title', 'created_at', 'update_at', 'position',)
     # permission_classes = (IsAuthorOrAdmin,)
@@ -136,7 +160,11 @@ class VideoViewSet(ExtendedModelViewSet):
     queryset = Video.objects.select_related(
         'course', 'lesson'
     ).all()
-    serializer_class = VideoSerializer
+    serializer_class = VideoCreateSerializer
+    serializer_class_map = {
+        'list': VideoSerializer,
+        'retrieve': VideoSerializer,
+    }
     search_fields = ('title',)
     ordering_fields = ('title', 'created_at', 'update_at', 'position',)
     # permission_classes = (IsAuthorOrAdmin,)
diff --git a/apps/course/migrations/0026_auto_20180208_1053.py b/apps/course/migrations/0026_auto_20180208_1053.py
new file mode 100644
index 00000000..60bac8b8
--- /dev/null
+++ b/apps/course/migrations/0026_auto_20180208_1053.py
@@ -0,0 +1,24 @@
+# Generated by Django 2.0.2 on 2018-02-08 10:53
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('course', '0025_course_gallery'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='course',
+            name='price',
+            field=models.DecimalField(blank=True, decimal_places=2, help_text='Если цена не выставлена, то курс бесплатный', max_digits=10, null=True, verbose_name='Цена курса'),
+        ),
+        migrations.AlterField(
+            model_name='material',
+            name='cover',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='material_covers', to='content.ImageObject', verbose_name='Обложка материала'),
+        ),
+    ]
diff --git a/apps/course/models.py b/apps/course/models.py
index a00250fe..61cca877 100644
--- a/apps/course/models.py
+++ b/apps/course/models.py
@@ -128,7 +128,11 @@ class Lesson(models.Model):
 
 class Material(models.Model):
     title = models.CharField('Название материала', max_length=100)
-    cover = models.ImageField('Фон материала', upload_to='materials')
+    cover = models.ForeignKey(
+        ImageObject, related_name='material_covers',
+        verbose_name='Обложка материала', on_delete=models.CASCADE,
+        null=True, blank=True,
+    )
     short_description = models.TextField('Краткое описание материала')
 
     created_at = models.DateTimeField(auto_now_add=True)
diff --git a/apps/user/models.py b/apps/user/models.py
index 141073ce..5986e33c 100644
--- a/apps/user/models.py
+++ b/apps/user/models.py
@@ -41,3 +41,6 @@ class User(AbstractUser):
 
     USERNAME_FIELD = 'email'
     REQUIRED_FIELDS = ['username']
+
+    class Meta(AbstractUser.Meta):
+        ordering = ('-date_joined',)
diff --git a/docker-compose.yml b/docker-compose.yml
index f42e5b6b..a6d65c69 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -28,7 +28,7 @@ services:
       - DATABASE_SERVICE_HOST=db
       - REDIS_SERVICE_HOST=redis
     ports:
-      - "8000:8000"
+      - "${PORT}:8000"
     depends_on:
       - db
       - redis