http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Humus, its structure and role in agriculture and environment
proceedings of the 10th Symposium Humus et Planta, held in Prague, in August 19-23, 1991
International Symposium "Humus et Planta" 1991 : Prague)
Developments in agricultural and managed-forest ecology ; v. 25