H. IBRAHIM ERKOVAN, M. TAN, M. BASRI HALITLIGIL, and H. KISLAL, “Performance of White-Clover Grasses Mixtures: Part-I Dry Matter Production, Botanical Composition, Nitrogen Use Efficient, Nitrogen Rate and Yield”, ajc, vol. 20, no. 5, pp. 4071–4076, Mar. 2010.