APA

Zivkov T., . (1981). Todor Zhivkov : A biogr. sketch. Sofia: Sofia Press.

Chicago

Zivkov Todor, . 1981. Todor Zhivkov : A biogr. sketch. Sofia: Sofia Press.

Harvard

Zivkov T., . (1981). Todor Zhivkov : A biogr. sketch. Sofia: Sofia Press.

MLA

Zivkov Todor, . Todor Zhivkov : A biogr. sketch. Sofia: Sofia Press. 1981.