Dange Bharat S., and Agrawal Surendra. “Experimental Study of Passive Heat Transfer Enhancement Technique With the Help of Various Factor by Using Twisted Tape Insert Inside a Tube in Tube Heat Exchanger”. International Journal of Advance Research in Engineering, Science & Technology, vol. 4, no. 4, Apr. 2017, pp. 658-67, https://ijarest.org/index.php/ijarest/article/view/1282.