SUDARDANA, I. K., and A. DANU ADJIANANDA. “UPAYA ROOM SERVICE DALAM MENINGKATKAN PELAYANAN SAAT PANDEMI COVID-19 DI GRAND PURI SARON BOUTIQUE HOTEL YOGYAKARTA”. JURNAL NUSANTARA, vol. 4, no. 2, Aug. 2021, pp. 14-32, https://jurnal.akparda.ac.id/index.php/nusantara/article/view/34.