Erratum to “Quantitative levonorgestrel plasma level measurements in patients with regular and prolonged use of the levonorgestrel-releasing intrauterine system” [Contraception 86 (2012) 345–349]

Beata Seeber, Stephanie C. Ziehr, Andreas Gschlieβer, Christina Moser, Verena Mattle, Christoph Seger, Andrea Griesmacher, Nicole Concin, Hans Concin, Ludwig Wildt⁎ Department of Gynecological Endocrinology and Reproductive Medicine, Innsbruck Medical University, A-6020 Innsbruck, Austria Department of Obstetrics and Gynecology, Innsbruck Medical University, Innsbruck, Austria Division of Mass Spectrometry and Chromatography, Institute of Medical and Chemical Laboratory Diagnostics (ZIMCL), University Hospital Innsbruck, Innsbruck, Austria Department of Obstetrics and Gynecology, Landeskrankenhaus Bregenz, Bregenz, Austria