APA

Vassilev W. A., Georgieva Z., Василев В. А., Georgieva Z., Георгиева Ж. & Vasilev V. A. (1979). Bulgaria - 13 centuries of existence. [София]: Sofia-Press.

Chicago

Vassilev Wassil A, Georgieva Zhechka, Василев Васил А, Georgieva Zecka, Георгиева Жечка and Vasilev Vasil A. 1979. Bulgaria - 13 centuries of existence. [София]: Sofia-Press.

Harvard

Vassilev W. A., Georgieva Z., Василев В. А., Georgieva Z., Георгиева Ж. and Vasilev V. A. (1979). Bulgaria - 13 centuries of existence. [София]: Sofia-Press.

MLA

Vassilev Wassil A, Georgieva Zhechka, Василев Васил А, Georgieva Zecka, Георгиева Жечка and Vasilev Vasil A. Bulgaria - 13 centuries of existence. [София]: Sofia-Press. 1979.