Metcalf M R, Tate L P, Sellett L C, Henry M
Department of Anatomy, Physiological Sciences and Radiology, College of Veterinary Medicine, North Carolina State University, Raleigh.
Equine Vet J. 1990 Jan;22(1):56-9. doi: 10.1111/j.2042-3306.1990.tb04209.x.