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Berg CJ, Bruce FC, Callaghan WM.Berg CJ, et al. Among authors: callaghan wm.J Am Med Womens Assoc (1972). 2002 Summer;57(3):173-4.J Am Med Womens Assoc (1972). 2002.PMID: 12146612
Dietz PM, Callaghan WM, Morrow B, Cogswell ME.Dietz PM, et al. Among authors: callaghan wm.Matern Child Health J. 2005 Sep;9(3):237-44. doi: 10.1007/s10995-005-0003-9.Matern Child Health J. 2005.PMID: 16078011