M. F. Pinto, E. H. G. Ponsano, A. P. da S. Almeida, S. H. V. Perri, and M. Shimokomaki, “Estrous characterization in cross-bred heifers (Bos taurus indicus x Bos taurus taurus) by radiotelemetry”, Braz. J. Vet. Res. Anim. Sci., vol. 43, no. 6, pp. 841–845, Dec. 2006, doi: 10.11606/issn.1678-4456.bjvras.2006.26564.