Isa Shuaibu, Mohammed, Aliyu Rafindadi Sanusi, and Maryam Bala Adamu. 2021. “Substitutability of Currency in Nigeria: A Non-Linear Approach”. Gusau International Journal of Management and Social Sciences 4 (3):18. https://gijmss.com.ng/index.php/gijmss/article/view/83.