1. Bergey D.H., Buchman R.F., Gibbons N.E.: Bergy's Manual of Determinative Bacteriology, 8th ed., pp. 683–701. Williams and Wilkins, Baltimore, 1974
2. Catcott E.V., Smithcors J.F.: Equine Medicine and Surgery, 2nd ed., pp. 620–621. American Veterinary Publication Incorporation, Illinois, 1972
3. Davis B.D., Dulbecco R., Eisen H.N., Ginsberg H.S., Wood W.B.: Microbiology, 2nd ed., pp. 861–862. Harper and Row, 1973