Abdou, Hamadou, Ekengele Nga Léopold, Mahamat Seid Ali Malloum, and Dieudonné Bitom. “Assessment of Heavy Metal Contamination Levels in Market Gardening Soils Used to Grow Onions (Allium Cepa) in the City of Abéché (Eastern Chad)”. International Journal of Applied Sciences and Biotechnology 11, no. 1 (March 31, 2023): 42–53. Accessed May 25, 2024. https://www.nepjol.info/index.php/IJASBT/article/view/53700.