4[4]Richard Laing, Brenda Waning, Andy Gray.25 years of the WHO essential medicines lists: progess and challenges[J]. Lancet, 2003,361:1 723.
5[5]Executive Board WHO.Revised procedures for updating the WHO model list of essential drugs: a summary of proposals and processes[R] . EB108/INF. DOC./2.Geneva :World Health Organization, 2001.