DeGregori, T. R. (2004). Origins of the organic agriculture debate. Blackwell.
Lua i Stíl Chicago (17ú heag.)DeGregori, Thomas R. Origins of the Organic Agriculture Debate. Iowa City: Blackwell, 2004.
Lua MLA (9ú heag.)DeGregori, Thomas R. Origins of the Organic Agriculture Debate. Blackwell, 2004.
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