@article{EndrikatParkeTrummerSchmidtDuijkersKlipping_2008,
title={Ovulation inhibition with four variations of a four-phasic estradiol valerate/dienogest combined oral contraceptive : results of two prospective, randomized, open-label studies},
author={Endrikat, Jan and Parke, Susanne and Trummer, Dietmar and Schmidt, Werner and Duijkers, Ingrid and Klipping, Christine},
doi={http://dx.doi.org/10.22028/D291-21153},
year={2008}
}