Osnovy formuvannja ukraïnsʹkoï movy v porivnjanni z inšymy schidnʹoslov'jansʹkymy movamy = Principles of formation of the Ukrainian language : in comparison with other Eastern Slavic languages - Kovaliv, Pantelejmon K. (Zapysky Naukovoho Tovarystva imeni Ševčenka, 1958)