Bambang Hengky Rainanto, Abdul Talib Bon, Jan Horas V. Purba. “Environmental Management System (EMS) and Green Marketing Mix (7Ps) for Hotel Sustainable Industrial Performance: A Conceptual Model”. International Journal of Advanced Science and Technology 29, no. 7s (May 1, 2020): 3724-3732. Accessed May 2, 2024. http://sersc.org/journals/index.php/IJAST/article/view/17697.