Koninckx, Philippe R.; Meuleman, Christel; Demeyere, Stephan; Lesaffre, Emmanuel; Cornillie, Freddy J. (April 1991). "Suggestive evidence that pelvic endometriosis is a progressive disease, whereas deeply infiltrating endometriosis is associated with pelvic pain". Fertility and Sterility. 55 (4): 759–765. doi:10.1016/s0015-0282(16)54244-7. PMID2010001.
Koninckx, Philippe R.; Meuleman, Christel; Demeyere, Stephan; Lesaffre, Emmanuel; Cornillie, Freddy J. (April 1991). "Suggestive evidence that pelvic endometriosis is a progressive disease, whereas deeply infiltrating endometriosis is associated with pelvic pain". Fertility and Sterility. 55 (4): 759–765. doi:10.1016/s0015-0282(16)54244-7. PMID2010001.