Nurul Hazwani Sabri et al. 2020. OPTIMAL PI TUNING RULES FOR LIQUID FLOW PROCESS CONTROL SYSTEM USING COHENCOON’S (C-C), ZIEGLER-NICHOLS’S (Z-N) AND TAKAHASHI’S TUNING METHOD. Malaysian Journal of Industrial Technology . 4, 1 (Jun. 2020), 1–6.