http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Handbook of vadose zone characterization and monitoring
edited by L.G. Wilson,Lorne G. Everett, Stephen J. Cullen.
Περιλαμβάνει βιβλιογραφικές παραπομπές και ευρετήριο.
Geraghty & Miller environmental science and engineering series