2Dellavale RP,Hester E J,Heilig LF,et al.Going,going,gone:lost internet reference.Science,2003,302 (5646):787-788.
3Crichlow R,Davies S,Winbush N.Accessibility and accuracy of web page reference in 5 major medical journals.JAMA,2004,292(22):2723-2724.
4Hester E J,Heilig LF,Drake AL,et al.Internet citations in oncology journals:a vanishing resource? J Natl Cancer Inst,2004,96(12):969-971.
5Schilling LM,Kelly DP,Heilig LF,et al.Digital information archiving policies in high-impact medical and scientific periodicals.JAMA,2004,292 (22):2724-2726.