Columbia subject headings:
Comparative linguistics.
Nostratic hypothesis.
Proto-Afroasiatic language.
Proto-Indo-European language.
Reconstruction (Linguistics)
Harvard subject headings:
Afroasiatic languages.
Proto-Indo-European language.
Reconstruction (Linguistics)
Princeton subject headings:
Afroasiatic languages.
Proto-Indo-European language.
Reconstruction (Linguistics)