A. Haque. Economics, Commerce and Trade Management: An International Journal (ECTIJ), volume 1 of IFIP Advances in Information and Communication Technology, page 15-25. https://airccse.com/ectij/papers/1117ectij02.pdf, (2017)
S. Goyal, N. Sachdeva, and T. Sachdeva. International Journal on Recent and Innovation Trends in Computing and Communication, 3 (4):
2255--2260(April 2015)