The diversity of Mycoplasma hyopneumoniae within and between herds using pulsed-field gel electrophoresis., Stakenborg, Tim, Vicca Jo, Butaye Patrick, Maes Dominiek, Peeters Johan, de Kruif Aart, and Haesebrouck Freddy , Vet Microbiol, 2005 Aug 10, Volume 109, Issue 1-2, p.29-36, (2005)