Helander, C. (2002). Farming system research: An approach to developing of sustainable farming systems and the role of white clover as a component in nitrogen management.
Lua i Stíl Chicago (17ú heag.)Helander, Carl-Anders. Farming System Research: An Approach to Developing of Sustainable Farming Systems and the Role of White Clover as a Component in Nitrogen Management. 2002.
Lua MLA (8ú heag.)Helander, Carl-Anders. Farming System Research: An Approach to Developing of Sustainable Farming Systems and the Role of White Clover as a Component in Nitrogen Management. 2002.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.