Columbia subject headings:
Harvard subject headings:
Afroasiatic languages--Etymology.
Afroasiatic languages--Grammar, Comparative--Sumerian.
Afroasiatic languages--History.
Sumerian language--Etymology.
Sumerian language--Grammar, Comparative--Afroasiatic.
Sumerian language--History.
Princeton subject headings:
Afroasiatic languages--Grammar, Comparative.
Sumerian language--Grammar, Comparative.