Media type: E-Article Title: Changes in the Structure of Weed Communities Affected by Agro-Chemicals: What Role Does Nitrogen Play? Contributor: Mahn, Ernst-Gerhard imprint: Munksgaard International Publishers Ltd., 1988 Published in: Ecological Bulletins Language: English ISSN: 0346-6868 Keywords: When Is a Plant a Weed? Origination: Footnote: