Detection of Leptospira spp. from pure cultures and from experimentally contaminated bovine semen by polymerase chain reaction - Heinemann, Marcos Bryan; Garcia, José Fernando; Nunes, Cáris Maroni; Higa, Zenaide Maria de Morais; Vasconcellos, Silvio Arruda; Richtzenhain, Leonardo José (Brazilian Journal of Veterinary Research and Animal Science, 1999)