Indra Jaya. “Culture to Serve Barometer Sustainability of North Sumatera and HANKAMNAS Development in Indonesia”. Britain International of Humanities and Social Sciences (BIoHS) Journal 2, no. 1 (February 8, 2020): 148-159. Accessed January 27, 2021. http://biarjournal.com/index.php/biohs/article/view/161.