Cita APA (7th ed.)
ebrary, Inc, Leith, J. A., Price, R. A., & Spencer, J. H. (1995). Planet earth: Problems and prospects. McGill-Queen's University Press.
Cita Chicago (17th ed.)
ebrary, Inc, James A. Leith, Raymond A. Price, i John H. Spencer. Planet Earth: Problems and Prospects. Montreal ; Buffalo: McGill-Queen's University Press, 1995.
Cita MLA (9th ed.)
ebrary, Inc, et al. Planet Earth: Problems and Prospects. McGill-Queen's University Press, 1995.
Atenció: Aquestes cites poden no estar 100% correctes.