Heinemann, M.B. et al. 1999. Detection of Leptospira spp. from pure cultures and from experimentally contaminated bovine semen by polymerase chain reaction. Brazilian Journal of Veterinary Research and Animal Science. 36, 1 (Jan. 1999), 15–18. DOI:https://doi.org/10.1590/S1413-95961999000100002.