Weibel, Daniel, Esther Schelling, Bassirou Bonfoh, Jürg Utzinger, Jan Hattendorf, Mahamat Abdoulaye, Toguina Madjiade, and Jakob Zinsstag. “Demographic and Health Surveillance of Mobile Pastoralists in Chad: Integration of Biometric Fingerprint Identification into a Geographical Information System”. Geospatial Health 3, no. 1 (November 1, 2008): 113-124. Accessed November 17, 2019. https://geospatialhealth.net/index.php/gh/article/view/237.