Differences in contraceptive prices between and within family planning outlets in urban and semiurban Nigeria: a prospective cohort studyAJOG Global Reports at a Glance oleh Claire W. Rothschild, PhD, MS, Bo Hu, PhD, Justin Archer, MSc, Ekerette Emmanuel Udoh, MPH, Chinedu Onyezobi, MRPP, Anthony Nwala, MPH, MBA