1. Accomazzi, A., Eichhorn, G., Kurtz, M. J., Grant, C. S., & Murray, S. S. (1999). The ADS bibliographic reference resolver. ASP conf. ser. 172: Astronomical data analysis software and systems VIII, p. 291
2. American Scientist Magazine 2004. On-line forum on open access literature, S. Harnad is the moderator. Available from
3. ArXiv 2004. Server usage statistics page. Available from
4. Usage analysis for the identification of research trends in digital libraries;Bollen;D-Lib Magazine,2003
5. Boyce, P. B. (1998). Urania, a linked, distributed resource for astronomy. ASP conf. ser. 153: Library and information services in astronomy III, p. 107