COnyango & Tolba Mostafa. (1992). The World environment 1972-1992: Two decades of challenge. Chapman & Hall.
Chicago Style (17th ed.) ZitazioaCOnyango eta Tolba Mostafa. The World Environment 1972-1992: Two Decades of Challenge. London: Chapman & Hall, 1992.
MLA (9th ed.) ZitazioaCOnyango eta Tolba Mostafa. The World Environment 1972-1992: Two Decades of Challenge. Chapman & Hall, 1992.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.