5Roger C.Schonfeld,Donald W.King,Ann Okerson,Eileen Giford Fenton Library Periodicals Expenses Comparison of NonSubscription Costs of Print and Electronic Form ats on a Life-Cycle Basis[J].D-Lib Magazine,2004,(1).
6Library and Archives of Canada.Records and Information Life Cycle Management[R].http://arxiv.org/ftp/cs/papers/0601/0601125.pdf.2006.
7Long-Lived Digital Data Collections:Enabling Research and Education in the 21st Century.Report of the National Science Board.http://www.nsf.gov/nsb/documents/2005/LLDD C_ report.pdf#.