1. M. Rizal, Herdis, Nasrullah, M. Riyadhi, I. Sangadji and Yulnawati, Indonesian Veterinary Journal 16, 249–255 (2015).
2. A. Boediono, Herdis and M. Rizal, Biotropia 23, 40–46 (2004).
3. Survival rate and antioxidant enzyme activity of ram spermatozoa after dilution with different extenders or selection by a dextran swim-up procedure
4. Herdis and I. W. Angga, Indonesian Journal of Science and Technology 14, 197–202 (2012)
5. Yulnawati, H. Maheshwari, M. Rizal and Herdis, Indonesian Veterinary Journal 11, 126–132 (2010)