???????, ????, ??? . 1984. ??????? ??????. ?????????????? ??????????? / ???????????????? ??????????? / Contrastive linguistics 9. (?????????????? ??????????? / ???????????????? ??????????? / Contrastive Linguistics). 126?127.

???????, ????, ??? . 1979. ?????????? ????? ???????????? ????????? ?? ??????? ? ?????????? ? ?????????? ????. ?????????????? ??????????? / ???????????????? ??????????? / Contrastive linguistics 4. (?????????????? ??????????? / ???????????????? ??????????? / Contrastive Linguistics). 3?14.

???????, ????, ??? . 1977. ??? ??????? ?? ??????????? ?????????? ? ???????????? ? ????????? ? ????????? ???? {(On the problem of the category transitivity ? intransitivity in English and in Bulgarian)}. ?????????????? ??????????? / ???????????????? ??????????? / Contrastive linguistics 2. (?????????????? ??????????? / ???????????????? ??????????? / Contrastive Linguistics). 92?113.