Bambang Hengky Rainanto, Abdul Talib Bon, Jan Horas V. Purba. 2020. “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 (7s), 3724-32. http://sersc.org/journals/index.php/IJAST/article/view/17697.