Levina, Arsyva, et al. “Understanding How User-Generated Content and Viral Marketing Drive Tumblers Purchase Decisions Among Gen Z: The Mediating Role of Sustainable Marketing”. Dinasti International Journal of Education Management and Social Science, vol. 7, no. 4, May 2026, pp. 3952-69, doi:10.38035/dijemss.v7i4.6680.