SCHKEEPER , A. E.; COLE , R. C.; BRAWNER , W. R.; GARD , J. A.; MAXWELL , H. S.; EDMONDSON , M. A. Ultrasound Anatomy of the Penis in Normal Bos Taurus Bulls. Clinical Theriogenology, v. 9, n. 4, p. 545-561, 1 Dec. 2017.