Agus Sulistiono, Yuniar Ayu Hafita, Ariandy Syamsul Bhahri, Wisnu Risianto, and Mustasyfa Thabib Kariadi, “Developing Maritime English Materials for Merchant Marine Polytechnic Students Based on Need Analysis”, Elementary Education Online, vol. 20, no. 1, pp. 1115–1122, Mar. 2021.