Degdo Suprayitno, Wibowo, Husein Umar. “Loyalty of Seafarers in the Shipping Industry in Jakarta Province, Indonesia”. 2020. PalArch’s Journal of Archaeology of Egypt Egyptology, vol. 17, no. 7, Jan. 2021, pp. 10065-84, https://archives.palarch.nl/index.php/jae/article/view/4045.