Al Hakim, R. R., Nasution, E. K., Rizaldi, R., & Rukayah, S. (2021). Provisioning food given by visitors to alpha-male long-tailed macaques at recreation forest, all of them are halal. Journal of Halal Product and Research (JHPR), 4(2), 50–58. https://doi.org/10.20473/jhpr.vol.4-issue.2.50-58