1. De Maddalena, C., Vodo, S., Petroni, A., & Aloisi, A. M. (2012). Impact of testosterone on body fat composition. Journal of cellular physiology227(12), 3744-3748. 
  2. Wittert, G. (2014). The relationship between sleep disorders and testosterone in men. Asian journal of andrology16(2), 262. 
  3. Roshanzamir, F., & Safavi, S. M. (2017). The putative effects of D-Aspartic acid on blood testosterone levels: A systematic review. International Journal of Reproductive BioMedicine15(1), 1. 
  4. Roaiah, M. F., El Khayat, Y. I., GamalEl Din, S. F., & Abd El Salam, M. A. (2016). Pilot study on the effect of botanical medicine (Tribulus terrestris) on serum testosterone level and erectile function in aging males with partial androgen deficiency (PADAM). Journal of sex & marital therapy42(4), 297-301. 
  5. Leung, K. W., & Wong, A. S. (2013). Ginseng and male reproductive function. Spermatogenesis3(3), e26391. 
  6. Jensen, M. B. (2012). Vitamin D metabolism, sex hormones, and male reproductive function. Reproduction144(2), 135-152. 
  7. Koehler, K., Parr, M. K., Geyer, H., Mester, J., & Schänzer, W. (2009). Serum testosterone and urinary excretion of steroid hormone metabolites after administration of a high-dose zinc supplement. European journal of clinical nutrition63(1), 65-70.