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Mathias CJ, Sun YZ, Welch MJ, Green MA, Thomas JA, Wade KR, Martell AE.Mathias CJ, et al.Int J Rad Appl Instrum B. 1988;15(1):69-81. doi: 10.1016/0883-2897(88)90163-8.Int J Rad Appl Instrum B. 1988.PMID: 3258304