In the current issue of D-Lib Magazine, a web journal for reasearch into digital libraries, Ann M. Lally and Carolyn E. Dunford at University of Washington Libraries describe how they have inserted external links into (the English) Wikipedia articles as a way to promote use of their library's website of digitized material.

"Using Wikipedia to Extend Digital Collections", http://dlib.org/dlib/may07/lally/05lally.html