Istriani, Rokhmah Nur, and Setya Rahardja. “Implementation Quality Management System of ISO 9001: 2015 at Vocational High School Yappi Wonosari Gunungkidul Regency”. KnE Social Sciences, vol. 3, no. 17, June 2019, pp. 478–485, doi:10.18502/kss.v3i17.4673.