B. Enya Ndem, B. Michael, and E. Onyemaechi Kevin , Trans., “Income Effect and Environmental Sustainability in Nigeria”, int.jour.sci.res.mana, vol. 5, no. 12, Dec. 2017, Accessed: Jun. 30, 2025. [Online]. Available: https://ijsrm.net/index.php/ijsrm/article/view/589