1 model
Journal
	refereed

2 model
Article
	doctype
	journal


Journal.objects.values('refereed').annotate(co_ref=Count('id', distinct=True), co_doctypes=Count('articles__doctype', distinct=True))


Journal.objects.values('articles__doctype', 'refereed').annotate(doc_counts=Count('articles__doctype'))


1 model
File
	experiment

2 model
FileAttribute
	title
	file

File.objects.values('experiment').annotate(co_exp=Count('id', distinct=True), co_titles=Count('attributes__title', distinct=True))

File.objects.values('attributes__title, 'experiment').annotate(title_counts=Count('attributes__title'))