Bett, R., Okeyo, M., Malmfors, B., Johansson, K., Agaba, M., Kugonza, D., Bhuiyan, A. K. F. H., Filho, A., Mariante, A., Mujibi, F., & Philipsson, J. (2013). Cattle Breeds: Extinction or Quasi-Extant? . Resources, 2(3), 335–357. https://doi.org/10.3390/resources2030335
Porter, V. & Mason, I. L. (2002). Mason’s World Dictionary of livestock breeds, types and varieties (5th ed.). Wallingford, Oxfordshire, UK: CABI.
Porter, V., Alderson, L., Hall, S. J. G., & Sponenberg, D. P. (2016). Mason’s World Encyclopedia of Livestock Breeds and Breeding: 2 volume pack (1st ed.). Wallingford, Oxfordshire, UK: CABI.