Keyyu, J., A. Kassuku, N. Kyvsgaard, A. Willingham, and G. Kifaro. “Genetic Resistance of Small East African Goats to Mixed Gastrointestinal Nematode Parasites”. Tanzania Veterinary Journal, vol. 18, no. 3, Sept. 1998, pp. 208-23, https://tvj.sua.ac.tz/vet2/index.php/TVJ/article/view/442.