Dabbang, P., and R. Varakusiripunth. “Packet Throughput In Hybrid Ds/Sfh Cdma Slotted Aloha Systems For Wireless Communications”. Journal of Engineering, RMUTT, vol. 2, Dec. 2002, pp. 101-6, https://ph01.tci-thaijo.org/index.php/jermutt/article/view/242381.