A. H. Rasheed, H. Alias, and S. D. Salman, “Effects of Coil Pitch Spacing on Heat Transfer Performance of Nanofluid Turbulent Flow through Helical Microtube Heat Exchanger”, IJET, vol. 7, no. 4.14, pp. 356–360, Dec. 2019, doi: 10.14419/ijet.v7i4.14.27674.