STEVENSON, F. Humus chemistry, genesis, composition, recictions / F.J. STEVENSON. New York.
Lua i Stíl Chicago (17ú heag.)STEVENSON, F.J. Humus Chemistry, Genesis, Composition, Recictions / F.J. STEVENSON. New York.
Lua MLA (8ú heag.)STEVENSON, F.J. Humus Chemistry, Genesis, Composition, Recictions / F.J. STEVENSON. New York.
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