AYTENEW, Mulugeta. Negative externalities of Synthetic Nitrogen Fertilizer on Human Civilization. Madda Walabu University Journal of Equity in Sciences and Sustainable Development, [S. l.], v. 2, n. 2, p. 63–69, 2018. Disponível em: https://jessdmwu.edu.et/MWU/index.php/files/article/view/23. Acesso em: 3 nov. 2025.