Cemex, S.A. de C.V, Conservation International, Agrupaci�on Sierra Madre, Mittermeier, R. A., & Robles Gil, P. (2002). Wilderness: Earth's last wild places (1st English ed.). CEMEX.

Cemex, S.A. de C.V, Conservation International, Agrupaci�on Sierra Madre, Russell A. Mittermeier, and Patricio Robles Gil. Wilderness: Earth's Last Wild Places. 1st English ed. Mexico City: CEMEX, 2002.

Cemex, S.A. de C.V, et al. Wilderness: Earth's Last Wild Places. 1st English ed. CEMEX, 2002.