Wardhana, A. S., H. . Amelinda Azizah, and C. N. . Hamdani. “Testing of Temperature Control System on Prototype of Heat Exchanger Based on PID”. Jurnal Otomasi Kontrol Dan Instrumentasi, vol. 13, no. 2, Oct. 2021, pp. 81-91, doi:10.5614/joki.2021.13.2.3.