Shamaki, Muazu Alhaji, and Katiman Rostam. 2013. “Factors Affecting Maternal Mortality In Sokoto State, Nigeria: Faktor-Faktor Yang Mempengaruhi Kematian Semasa Hamil Di Negeri Sokoto, Nigeria”. GEOGRAFI 1 (2):59-70. https://ejournal.upsi.edu.my/index.php/GEOG/article/view/455.