Indrayana, M. “Classic Performing Arts Supply Chain Modeling in Covid 19 Protocol to Support D.I Yogyakarta Cultural Tourism Using Soft System Methodology”. Avant-Garde: Jurnal Ilmiah Pendidikan Seni Pertunjukan, vol. 2, no. 2, May 2024, pp. 177-84, doi:10.24036/ag.v2i2.135.