TY - JOUR T1 - When considering attacks against the National Breast Screening Study, consider the sources JF - Canadian Medical Association Journal JO - CMAJ SP - 427 LP - 428 VL - 148 IS - 3 AU - B. Goldman Y1 - 1993/02/01 UR - http://www.cmaj.ca/content/148/3/427.abstract ER -