1. Biester H.E., Schwarte L.H.: Diseases of Poultry, pp. 872–873. Iowa State University Press. Ames. Iowa, 1967.
2. A Light Microscopic Study of Bovine Peripheral Nerve Sheath Tumours
3. Jubb K.V.F., Kennedy P.C.: Pathology of Domestic Animals, pp. 433–437, 2nd ed. Academic Press, New York, 1970.