Venkatesh Babu S., A. Philomina Jenifer, P. K. Santhosh, Jeba Christla S., Kanagavalli R. “Performance BER Analysis of Spectrum Cognitive Radio Networks ”. International Journal of Control and Automation, Vol. 13, no. 03, Apr. 2020, pp. 432-9, http://sersc.org/journals/index.php/IJCA/article/view/38115.