Al Hakim, R.R., Nasution, E.K., Rizaldi, R. and 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 (Dec. 2021), 50–58. DOI:https://doi.org/10.20473/jhpr.vol.4-issue.2.50-58.