Adi Pratama, A., S. Sunyoto, and S. Sumarman. “Analisis Implikasi Peran Standard Operating Procedure (SOP) Terhadap Tingkat Kualitas Kerja Bagi Room Attendant Pada Housekeeping Department Di Hotel Novotel Solo”. Jurnal Pariwisata Indonesia, vol. 12, no. 1, June 2016, pp. 77-102, http://jurnal.stpsahidsurakarta.ac.id/index.php/JPI/article/view/206.