4Yoong W, Karavolos S,Damodaram M. Observer accuracy andHowaccurate and consistent are health - care professionals. [J].Archives of Gynecology and Obstetrics,2010(9): 12 - 13.
6The Joanna Briggs Institute. The management of nipple painand/or trauma associated with breastfeeding [J]. Best PracticeEvidence - based Information Sheets for Health Professionals,2009,13(4) ;1 -4.