FEJES, Annamária. A „létratechnika" Marketing and Research Today, 1997. augusztus. Marketing & Menedzsment, [S. l.], v. 32, n. 1, p. 79–80, 2019. Disponível em: https://journals-test.lib.pte.hu/index.php/mm/article/view/2210. Acesso em: 23 dec. 2024.