Franke, L.B. and Saibro, J.C. de 1997. Effect of phosphorus and of irrigation on alfalfa seed yield. Pesquisa Agropecuaria Brasileira. 32, 12 (Dec. 1997), 1263–1272. DOI:https://doi.org/10.1590/S1678-3921.pab1997.v32.4782.