article 1996 Reliability and Validity of the Functional Pelvic Pain Scale: A New Measure of Pelvic Pain Severity ·doi:10.1016/s0849-5831(16)30250-6
article 1995 The Need for a Valid Classification System for Endometriosis and Pelvic Pain ·doi:10.1016/s1701-2163(16)30557-6