Bahamondes L, Bahamondes MV, Monteiro I (2008). "Levonorgestrel-releasing intrauterine system: uses and controversies". Expert Review of Medical Devices. 5 (4): 437–445. doi:10.1586/17434440.5.4.437. PMID18573044. S2CID659602.
Wingo PA, Huezo CM, Rubin GL, Ory HW, Peterson HB (1985). "The mortality risk associated with hysterectomy". American Journal of Obstetrics and Gynecology. 152 (7 Pt 1): 803–808. doi:10.1016/s0002-9378(85)80067-3. PMID4025434.
Bahamondes L, Bahamondes MV, Monteiro I (2008). "Levonorgestrel-releasing intrauterine system: uses and controversies". Expert Review of Medical Devices. 5 (4): 437–445. doi:10.1586/17434440.5.4.437. PMID18573044. S2CID659602.
Wingo PA, Huezo CM, Rubin GL, Ory HW, Peterson HB (1985). "The mortality risk associated with hysterectomy". American Journal of Obstetrics and Gynecology. 152 (7 Pt 1): 803–808. doi:10.1016/s0002-9378(85)80067-3. PMID4025434.