3Sally A.Rogers Electronic Journal Usage at Ohio State University.College&Libraries Research,2001(1).
4Titia Van der Werf—Davelaar Long—term preservation of electonic publications:the nedlib project D—Lib Magazine,1999,5(9)http://www.dlib.org.
5Jasen B.J,et al real life,real users,real needs.a study and analysis of user queries on the web.Informaiton Processing and Management,2000(36).
6Karen Ruppa-Serrano.Canceling print serials in favor of electronic:criteria for decision making.Library Collections,Acquisitions & Technical Services,2002,26:369-378
7William Fisher Now you see it;now you don't:the elusive nature of electronic information.Library Collections,Acquisitions,& Technical Services 2003,27:463-472