Viana, C. H. C., Arruda, R. P. de, Moretti, A. S., & Visintin, J. A. (1998). Ovarian cysts, rectal palpation and ultra-rectal ultra- sonography diagnosis in sows: literature review and two clinical report studies. Brazilian Journal of Veterinary Research and Animal Science, 35(2), 64-68. https://doi.org/10.1590/S1413-95961998000200003