Nak-Yun Sung, Eui-Hong Byun, Sun-Kyu Kwon, Beom-Seok Song, Jong-il Choi, Jae-Hun Kim, Myung-Woo Byun, Young-Choon Yoo, Mee-Ree Kim and Ju-Woon Lee
Radiation Physics and Chemistry 78 ( 7 ): 433 - 436 , 2009