Columbia subject headings:
Indo-European languages--Grammar, Comparative--Slavic.
Slavic languages--Etymology.
Slavic languages--Grammar, Comparative--Indo-European.
Harvard subject headings:
Princeton subject headings:
Indo-European languages--Phonology, Comparative--Slavic.
Proto-Slavic language--Phonology, Historical.
Slavic languages--Phonology, Comparative--Indo-European.