Model fields: https://docs.djangoproject.com/en/2.1/ref/models/fields/
QuerySet API: https://docs.djangoproject.com/en/2.1/ref/models/querysets/
Class based views: https://docs.djangoproject.com/en/2.1/topics/class-based-views/intro/
Generic class based views: https://docs.djangoproject.com/en/2.1/ref/class-based-views/
QuerySets: https://docs.djangoproject.com/en/2.1/topics/db/queries/