Clippinger T L, Bennett R A, Newell S M
Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville 32610-0126, USA.
Vet Radiol Ultrasound. 1998 May-Jun;39(3):181-4. doi: 10.1111/j.1740-8261.1998.tb00336.x.