Dyfyniad APA

ebrary, Inc, Bennett, R. J., & Estall, R. C. (1991). Global change and challenge: Geography for the 1990s. Routledge.

Dyfyniad Arddull Chicago

ebrary, Inc, R. J. Bennett, and Robert C. Estall. Global Change and Challenge: Geography for the 1990s. London ; New York: Routledge, 1991.

Dyfyniad MLA

ebrary, Inc, et al. Global Change and Challenge: Geography for the 1990s. Routledge, 1991.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.