FIRDAUS, M.; WAHAB, Z.; WIDIYANTI, M.; SHIHAB, M. S. Effect of price and promotion on customer loyalty of domestic and export coal in the time of the COVID-19 pandemic. International journal of social sciences, [S. l.], v. 5, n. 1, p. 8-14, 2022. DOI: 10.21744/ijss.v5n1.1820. Disponível em: https://sloap.org/journal/index.php/ijss/article/view/1820. Acesso em: 16 jul. 2024.