Muhasain, Zaid Abed Aljasim, and Saif Abed Aljasim Muhasain. “Analysis and Design of Controller for Level Process Control Without Sensor”. Al-Nahrain Journal for Engineering Sciences, vol. 13, no. 1, Mar. 2010, pp. 84-97, https://nahje.com/index.php/main/article/view/582.