4Report of the World Commission on Environment and Development[EB/OL]. [2014-12-15]. http://www.un.org/documents/ ga/res/42/ares42-187.htm/.
5McArthur D J, Giersch S, Burrows H. Sustainability Issues and Activities for the NSDL[C].Joint Conference on Digital Libraries, 2003.
6Chowdhury G. Sustainability of Digital Libraries: A Conceptual Model and A Research Framework[J]. International Journal on Digital Libraries, 2014, 14(3-4): 181-195.
7Sharma R K, Vishwanathan K R. Digital Libraries: Development and Challenges[J]. Library Review, 2001, 50(3): 10-15.
8Francis H. Digital Libraries: Opportunities and Challenges for the English-speaking Caribbean[J]. Information Development, 2008, 24(2): 143-150.
9Swan A. Modelling Scholarly Communication Options: Costs and Benefits for Universities[R/OL]. [2014-12-21].http://repository.jisc. ac.uk/442/2/Modelling_scholarly_communication_report_final 1. pdf.
10Houghton J W. The Costs and Potential Benefits of Alternative Scholarly Publishing Models[J]. Information Research, 2011, 16(1): 469.