Vitti, Dorinha Miriam Silber Schmidt, et al. “Evaluation of the Availability of Phosphorus from Dicalcium Phosphate and Rock Phosphates for Sheep, Using Radiophosphorus (³²P) As Tracer”. Pesquisa Agropecuaria Brasileira, vol. 26, no. 8, Aug. 1991, pp. 1113-8, doi:10.1590/S1678-3921.pab1991.v26.3446.