Govasmark, Espen; Steen, Arvid; Bakken, Anne Kjersti; Strøm, Turid; Hansen, Sissel and Bernhoft, Aksel (2005) Copper, molybdenum and cobalt in herbage and ruminants from organic farms in Norway. Acta Agriculturae Scandinavica Section A Animal Science, 55, pp. 21-30.