DR UMAR MOHAMMED ALI. THE APPROACHES USED IN MEASURING OR ESTIMATING NATIONAL INCOME OF A NATION. Frontline Marketing, Management and Economics Journal, [S. l.], v. 2, n. 04, p. 6–15, 2022. DOI: 10.37547/marketing-fmmej-02-04-02. Disponível em: https://frontlinejournals.org/journals/index.php/fmmej/article/view/178. Acesso em: 13 sep. 2025.