Cita APA (7th ed.)

Greenwood, N. H., & J.M.B. Edwards. (1979). Human environments and natural systems (2nd ed.). Duxbury Pr..

Cita Chicago (17th ed.)

Greenwood, N. H., i J.M.B. Edwards. Human Environments and Natural Systems. 2nd ed. North Scituate, Mass: Duxbury Pr., 1979.

Cita MLA (9th ed.)

Greenwood, N. H., i J.M.B. Edwards. Human Environments and Natural Systems. 2nd ed. Duxbury Pr., 1979.