Cell phone ownership and modern contraceptive use in Burkina Faso: implications for research and interventions using mobile technology. Greenleaf, Abigail R; Ahmed, Saifuddin; Moreau, Caroline; Guiella, Georges; Choi, Yoonjoung. Contraception. 2019; 99: p.170-174. doi:10.1016/j.contraception.2018.11.006Article