ebrary, Inc, Leith, J. A., Price, R. A., & Spencer, J. H. (1995). Planet earth: Problems and prospects. McGill-Queen's University Press.

ebrary, Inc, James A. Leith, Raymond A. Price, and John H. Spencer. Planet Earth: Problems and Prospects. Montreal ; Buffalo: McGill-Queen's University Press, 1995.

ebrary, Inc, et al. Planet Earth: Problems and Prospects. McGill-Queen's University Press, 1995.