“BY USING HELICAL BAFFLE ON THE ANNULAR SPACE OF A DOUBLE PIPE HEAT EXCHANGER TO IMPROVE THE HEAT TRANFER CHARACTERISTICS”. INTERNATIONAL JOURNAL OF PETROCHEMICAL ENGINEERING AND TECHNOLOGY (IJPET), vol. 1, no. 1, Jan. 2020, pp. 1-4, https://lib-index.com/index.php/IJPET/article/view/IJPET_01_01_001.