Driyono, Bambang, and Muh. Nafkar Jaya. “Innovation Design of Digital Clinometer Papi (Precision Approach Path Indicator) Angle Measurer Instrument at Yogyakarta Adisutjipto International Airport”. Airman: Jurnal Teknik dan Keselamatan Transportasi 3, no. 1 (June 30, 2020): 88–95. Accessed September 19, 2024. https://jurnal.poltekbangmakassar.ac.id/index.php/airman/article/view/160.