Hofmeyr, G. ., Morrison, C. ., Baeten, J. ., Chipato, T. ., Donnell, D. ., Gichangi, P. ., … Trial, T. E. (2017). Rationale and design of a multi-center, open-label, randomised clinical trial comparing HIV incidence and contraceptive benefits in women using three commonly-used contraceptive methods (the ECHO study). Gates Open Research, 1, 17. https://doi.org/10.12688/gatesopenres.12775.1 (Original work published 2017)