Columbia subject headings:
Arabic language--Dialects--Sudan--Conversation and phrase books.
Arabic language--Dialects--Sudan--Glossaries, vocabularies, etc.
Arabic language--Dialects--Sudan--Grammar.
Harvard subject headings:
Arabic language--Dialects--Sudan--Glossaries, vocabularies, etc.
Arabic language--Dialects--Sudan--Grammar.
Arabic language--Textbooks for foreign speakers--English.
Princeton subject headings: