1. F Burdan. Developmental effects of propyphenazone in analgesic and antipyretic combination with caffeine or paracetamol. Hum Exp Toxicol. 2004 May;23(5):235-44. 2. Mohamed F Radwan, et al. Propyphenazone-based analogues as prodrugs and selective cyclooxygenase-2 inhibitors. ACS Med Chem Lett. 2014 Jun 23;5(9):983-8.