P. Thanh Nguyen, H. Herman, Q. L. H. Thuy To Nguyen, I. Wayan Suparta, y V. D. Bich Huynh, «Cleanliness Assessment of Sub-District in Regency Using Technique for Order Preference by Similarity to Ideal Solution», Opción, vol. 35, pp. 2899-2921, jun. 2019.