Опит за изучаване на първобългарските следи в българския и карачаево-балкарския език

o far Bulgarian linguistics has looked for traces of Proto-Bulgarian primarily in the {\v C}uva{\v s} language as a mediator. The authors of the paper abandon this approach and investigate the linguistic and historical connection between Bulgarian and the Balkar-Kara{\v c}aev language. As a result of that novel approach a number of new words, both from the onomastic and non-onomastic classes have been added to the established Proto-Bulgarian ones: b{\u a}lgarin b{\u a}alk{\u a}ar, m{\u a}alk{\u a}ar, kopanec, {\v c}eren tatarin, {\v c}avka, taj{\v c}e, Tangra-Tejri, Atila, Asparuh, {\v S}ibil, Kospartov and {\v S}abla. It was found that for the purposes of defining more accurately the Proto-Bulgarian lexical layer, the Kara{\v c}aevo-Balkar language offers a number of advantages as compared to {\v C}uva{\v s}. Evidence was also found to substantiate the claim that the Kara{\v c}aevo-Balkar language is the most suitable mediator for studies of the Rumanian substratum of the Bulgarian language.