NASSER S. IBRAHIM, A. Pyramid Marketing Via Internet and its Effect on clients. مجلة دراسات إقلیمیة, [S. l.], v. 9, n. 26, p. 279–316, 2012. DOI: 10.33899/regs.2012.35987. Disponível em: https://regs.uomosul.edu.iq/index.php/regs/article/view/48268. Acesso em: 17 oct. 2025.