APA

Hettena P. H. G., Syer G. N. & Conservation Society. (1971). Decade od decision. London: The Conservation Society.

Chicago

Hettena P H G, Syer G N and Conservation Society. 1971. Decade od decision. London: The Conservation Society.

Harvard

Hettena P. H. G., Syer G. N. and Conservation Society. (1971). Decade od decision. London: The Conservation Society.

MLA

Hettena P H G, Syer G N and Conservation Society. Decade od decision. London: The Conservation Society. 1971.