Craig, J. R. 1., Skinner, B. J. 1., Vaughan, D. J. 1., Vaughan, D. J., Skinner, B. J., Skinner, B. J., & Vaughan, D. J. (1996). Resources of the earth (2nd ed.). Upper Saddle River, N.J.: Prentice Hall.

Craig, James R. 1940-, Brian J. 1928- Skinner, David J. 1946- Vaughan, David J. Vaughan, Brian J. Skinner, Brian J. Skinner, and D. J. Vaughan. Resources of the Earth. 2nd ed. Upper Saddle River, N.J.: Prentice Hall, 1996.

Craig, James R. 1940-, et al. Resources of the Earth. 2nd ed. Upper Saddle River, N.J.: Prentice Hall, 1996.