Schenker, Alexander M.Proto-Slavonic / Comrie, Bernard; Corbett, Greville. G. — The Slavonic Languages. — London: Routledge, 2002. — С. 82.
Schenker, Alexander M.Proto-Slavonic / Comrie, Bernard; Corbett, Greville. G. — The Slavonic Languages. — London: Routledge, 2002. — С. 75. — ISBN 0-415-28078-8.