AHMED, Q. M.; HAIDER HUSSAIN, M. Estimating the Black Economy through a Monetary Approach: A Case Study of Pakistan. Economic Issues, [S. l.], v. 13, n. 1, p. 45–60, 2008. Disponível em: http://economicissues.org.uk/index.php/EI_OJS/article/view/145. Acesso em: 23 oct. 2026.