Moreira, Adônis, et al. “Influence of Calcium: Magnesium Ratio in Limestone on Nodulation, Dry Matter Yield and Mineral Composition of Alfalfa”. Pesquisa Agropecuaria Brasileira, vol. 34, no. 2, Feb. 1999, pp. 249-55, https://doi.org/10.1590/S1678-3921.pab1999.v34.5153.