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Mulholland GK, Jewett DM, Toorongian SA.Mulholland GK, et al.Int J Rad Appl Instrum A. 1988;39(5):373-9. doi: 10.1016/0883-2889(88)90065-2.Int J Rad Appl Instrum A. 1988.PMID: 2840412Free article.