Buol, S. S., Southard, R. R., Graham, R. R., & McDaniel, P. P. (2003). Soil genesis and classification (fifth edition.).

Buol, S.W. Stanley, R.J. Randal Southard, R.C. Robert Graham, and P.A. Paul McDaniel. Soil Genesis and Classification. fifth edition. 2003.

Buol, S.W. Stanley, et al. Soil Genesis and Classification. fifth edition. 2003.