Ace Com. (1992). Agenda 21: Enviroment. Ace Communication.
Cita Chicago (17th ed.)Ace Com. Agenda 21: Enviroment. Nairobi, kenya: Ace Communication, 1992.
Cita MLA (9th ed.)Ace Com. Agenda 21: Enviroment. Ace Communication, 1992.
Atenció: Aquestes cites poden no estar 100% correctes.