z39.50-1995: Information retrieval protocol. by Juha Hakala. January 1996

An overview of the z39.50 Information Retrieval Standard by Fay Turner, Revised, June 1996

z39.50 in a Nutshell - (an introduction to z39.50 ) by John A Kunze  and R P C Rodgers, July 1995

The z39.50 Protocol: literature review by Michael L Smith, Nov 1996. http://istweb.syr.edu/~ist667/z3950.htm

z39.50 Search and Retrieval protocol-an update. by Andrew Wells, NSP project. 
http://www.nla.gov.au/nla/staffpaper/awells1.html

z39.50 : An overview of development and the future by Iltsis, Susannah.

z39.50 and the World Wide Web. by Hammer, Sebastian and John Favaro.
Arts and Humanities Data Service.http://ahds.ac.uk/

Melvyl http://www.melvyl.ucop.edu/

AHDS Gateway http://prospero.ahds.ac.uk:8080/ahds_live/

California Digital Library http://www.cdlib.org/