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)