VALENTIN KULIKOV. Client Happiness as a Predictive Economic Variable in Revenue Systems. Journal of Economics, Finance and Accounting Studies , [S. l.], v. 8, n. 5, p. 29–49, 2026. DOI: 10.32996/jefas.2026.8.5.4. Disponível em: https://al-kindipublishers.org/index.php/jefas/article/view/12597. Acesso em: 1 jun. 2026.