1. 1) Buchanan, J.W. and Bücheler, J. 1995. J. Am. Vet. Med. Assoc. 206: 194-199.
2. 2) Darke, P., Bonagura, J. D. and Kelly, D. F. 1996. pp. 24-31. In: Color Atlas of Veterinary Cardiology. Mosby-Wolfe, London.
3. 3) Ettinger, S. J. and Suter, P. F. 1970. pp. 214-216. In: Canine Cardiology. W. B. Saunders, Philadelphia.
4. 4) Feigenbaimum, H. 1994. pp. 251-262. In: Echocardiography, 5th ed., Lea & Feiger, Philadelphia.
5. 5) Miyatake, K., Izumi, S., Okamoto, M., Kinoshita, N., Asonuma, H., Nakagawa, H., Yamamoto, K., Takamiya, M., Sakakibara, H. and Nimura, Y. 1986. J. Am. Coll. Cardiol. 7: 82-90.