Franke, Lucia Brandão, and João Carlos de Saibro. “Effect of Phosphorus and of Irrigation on Alfalfa Seed Yield”. Pesquisa Agropecuaria Brasileira, vol. 32, no. 12, Dec. 1997, pp. 1263-72, doi:10.1590/S1678-3921.pab1997.v32.4782.