Pinto, Marcos Franke, et al. “Estrous Characterization in Cross-Bred Heifers (Bos Taurus Indicus X Bos Taurus Taurus) by Radiotelemetry”. Brazilian Journal of Veterinary Research and Animal Science, vol. 43, no. 6, Dec. 2006, pp. 841-5, https://doi.org/10.11606/issn.1678-4456.bjvras.2006.26564.