APA

Petkov K., Thirkell J. & Kanazireva P. (1988). The Brigade Organization of Work in Bulgaria. : Sofia Press.

Chicago

Petkov Krustyu, Thirkell John and Kanazireva P. 1988. The Brigade Organization of Work in Bulgaria. : Sofia Press.

Harvard

Petkov K., Thirkell J. and Kanazireva P. (1988). The Brigade Organization of Work in Bulgaria. : Sofia Press.

MLA

Petkov Krustyu, Thirkell John and Kanazireva P. The Brigade Organization of Work in Bulgaria. : Sofia Press. 1988.