van der Merwe, PJ, and E Grobbelaar. 2003. “Stability of 19-Norandrosterone and 19-Noretiocholanolone Glucuronide in Urine under Various Storage Conditions”. South African Journal of Sports Medicine 15 (2):14-17. https://doi.org/10.17159/2078-516X/2003/v15i2a217.