3Barbara A. Winters. Access and ownership in the 21st century: development of virtual collection in consortial settings. In:Ching- Chih Chen ed. Electronic Resources and Consortia.Taipei: Science and Technology Infommtion Center, 1999.
4O.Gene Norman. The impact of electronic information sources on collection development: a stagey of current practice. Library Hi Tech, 1997, 15(1-2): 123-132.
5Cynthia Dobson et al. Collection evaluation for interdisciplinary fields: a comprehensive approach. The Journal of Academic Librarianship, 1996, 22(4) : 279 - 284.
6Karen Svenningsen. An evaluation model for electronic resources utilizing cost analysis. The Bottom Line: Managing Library Finances, 1998,11(1): 18-23.
7Gary Geisler et al. Creating virtual collections in digital libraries: benefits and implementation issues. Proceeding of the Second ACM/IEEE - CS Joint Conference on Digital Libraries, July14-18, 2002,Portland: 210-218.
8Candy Schwartz. Digital libraries: an overview. The Journal of Academic Librarianship, 2000,26(6) : 385 - 393.
9Smith, Alastair G. Testing the Surf: Criteria for Evaluating Internet Information Resources. The Public - Access Computer Sys tems Review 8, no. 3 (1997).
10Roswitha Poll. Measuring impact and outcome of libraries. Performance Measurement and Metrics, Volume 4. Number 1. 2003. PP. 5 -12.
5California Digital Library: Key Indicaors of Collections and Use [EB/OL].http://www.cdlib.org/services/collections/usage stats/docs/fy01-02cdl_statsprofile.pdf, 2012 - 10-11.
6E- Metrics: Measures for Electronic Resources[EB/OL]. http:// uksg.metapress.com/content/nfSquwaf36aurpbn/, 2012-10-11.
