@article {Прокопиева1978,
	title = {Вокални инфикси в българския и руския език},
	journal = {Съпоставително езикознание / Сопоставительное языкознание / Contrastive linguistics},
	volume = {3},
	year = {1978},
	pages = {35{\textendash}44},
	abstract = {The study of the vocal element in the root structure of the {\quotedblbase}consonant-vocal-consonant{\textquotedblleft} type in Bulgarian and Russian by statistic methods shows that three vowels o, e, a are most frequently used. This is a characteristic feature of both Bulgarian and Russian, although the differences in the frequency of о and e in Russian and Bulgarian, when checked by the Student t-criterion, may prove considerable. O occurs more frequently in nominal stems than in verbal stems, which obviously proves that this vowel has preserved, to a certain extent, the old Indo-European semantic connection with nominalization, typical mainly of nouns. As far as the frequency of e is concerned, the results are rather unexpected. Usually, in Indo-European studies e marks action and is connected, first of all, with the verb. In the statistical data processing, the frequency of e in verbs has turned out to be higher than the frequency of e in nouns in both languages; however, the negligible deviation of the t-criterion test shows that there is no significant difference between the use of e in verbs and nouns. The vowel a in the roots of the type under investigation is practically equally frequent; it has also an even distribution in the verbal and nominal stems in the two languages.},
	author = {Прокопиева, Татяна}
}
