Allen, J. (1990). Environment 90/91. The Duskin.
Cita Chicago (17th ed.)Allen, John. Environment 90/91. The Duskin, 1990.
Cita MLA (9th ed.)Allen, John. Environment 90/91. The Duskin, 1990.
Atenció: Aquestes cites poden no estar 100% correctes.
Cita APA (7th ed.)