RUSKOV, P.; BOEVSKY, I. Digital Transformation of CRM and Transition to e–CRM. Economy and Business Yearbook, [S. l.], v. 7, p. 189–217, 2022. DOI: 10.33919/EcoBY.22.7.14. Disponível em: https://ojs.nbu.bg/index.php/EcoBY/article/view/1330. Acesso em: 9 dec. 2025.