http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
proceedings of a symposium sponsored by Divisions S-5 and S-9 of the Soil Science Society of America in San Antonio, Texas, 21-26 Oct. 1990
xii, 159 p., [12] p. de láms. : il. (algunas col.) ; 23 cm.
editors, J.M. Bigham and E.J. Ciolkosz ; organizing committee, J.M. Bigham ; editor-in-chief SSSA, R.J. Luxmoore.