Rarintip Sirisukpoca. 2008. Improvement of GPRS international roaming process using lean six sigma approach. Faculty of Engineering, Chulalongkorn University;
Rarintip Sirisukpoca. (2008) Improvement of GPRS international roaming process using lean six sigma approach . Chulalongkorn University/Bangkok.
Rarintip Sirisukpoca. Improvement of GPRS international roaming process using lean six sigma approach. . Bangkok:Chulalongkorn University, 2008.
Rarintip Sirisukpoca. (2008) Improvement of GPRS international roaming process using lean six sigma approach . Chulalongkorn University/Bangkok.