P. ASTUTI, T. L. YUSUF, E. HAYES, H. MAHESHWARI, L. SJAHFIRDI, and D. SAJUTHI, “Diurnal Patterns of Testosterone and Cortisol Metabolites in Fecal of Javan Gibbons (Hylobates moloch) in Captivity”, HAYATI J Biosci, vol. 13, no. 2, p. 69, Dec. 2009, doi: 10.4308/hjb.13.2.69.