Attia, John O., Dhadesugoor Vaman, and Matthew N. O. Sadiku. “Engineering Standards: An Introduction for Electrical and Computer Engineering Students”. European Scientific Journal, ESJ 13, no. 9 (March 31, 2017): 325. Accessed August 8, 2020. http://eujournal.org/index.php/esj/article/view/9028.