Hussein, Nassr, and Abdulrahman Mahmood. “Enhancing Heat Transfer in Tube Heat Exchanger by Inserting Discrete Twisting Tapes With Different Positions”. Journal of Engineering 25, no. 8 (July 31, 2019): 39-51. Accessed January 23, 2020. http://joe.uobaghdad.edu.iq/index.php/main/article/view/j.eng.2019.08.03.