APA
General conference. 22nd session (Belgrade 1., .Draft programme and budget for 1981-1983. Paris: United Nations Educational Scientific and Cultural Organisations France.
Chicago
General conference. 22nd session (Belgrade 1980), .Draft programme and budget for 1981-1983. Paris: United Nations Educational Scientific and Cultural Organisations France.
Harvard
General conference. 22nd session (Belgrade 1., .Draft programme and budget for 1981-1983. Paris: United Nations Educational Scientific and Cultural Organisations France.
MLA
General conference. 22nd session (Belgrade 1980), .Paris: United Nations Educational Scientific and Cultural Organisations France. .