letter 2011 Letter in response to Levonorgestrel-releasing intrauterine system (Mirena®) and Depot medroxyprogesterone acetate (Depo-Provera) as long-term maintenance therapy for patients with moderate and severe endometriosis: a randomised trial by Wong AYK, Tang LC The Australian & New Zealand journal of obstetrics & gynaecology ·doi:10.1111/j.1479-828x.2010.01240.x