1. Kamphues, J. (1999). Berliner und MuÉnchener TieraÉrztliche, 112, 370–379.
2. Joshi, V. K., Gupta, K., Devrajan, A., Lal, B. B., & Arya, S. P. (2000). Journal of Food Science and Technology, 37, 609–612.
3. Saha, S. K., Senani, S., Padhi, M. K., Shome, B. R., Shome, R., & Ahlawat, S. P. S. (1999). Current Science, 77, 696–697.
4. Kung, L. (1998). In S. Muirhead (Ed.), Direct-fed microbial, enzyme & forage additive compendium, vol.4: Direct-fed microbial and enzyme feed additives pp. 15–19. Minnesota, USA: Miller.
5. Martin, S. A., & Nisbet, D. J. (1992). Journal of Dairy Science, 75, 1736–1744.