Cita APA (7a ed.)

Martin, F., & Whittle, A. (1989). Skills in geography (1. publ.). Heinemann.

Cita Chicago Style (17a ed.)

Martin, Fred, y Aubrey Whittle. Skills in Geography. 1. publ. London: Heinemann, 1989.

Cita MLA (9a ed.)

Martin, Fred, y Aubrey Whittle. Skills in Geography. 1. publ. Heinemann, 1989.