Abdul Razak Omar, Mahyudin Omar, Ahmad Shaharudin Abdul Latif, Anim Zalina Azizan, and Muhammad Suhaimi Sulong, MODUL INSTRUMEN DIAGNOSTIK USAHAWAN BERJAYA. Penerbit UTHM, 2017. Accessed: Aug. 26, 2026. [Online]. Available: https://monograph.uthm.edu.my/index.php/penerbituthm/catalog/book/195