Possibly of interest, NISO will be working on a standard for the coding of citations in ebooks: http://www.niso.org/publications/isq/2011/v23no4/lagace kc -- Karen Coyle kcoyle at kcoyle.net http://kcoyle.net ph: 1-510-540-7596 m: 1-510-435-8234 skype: kcoylenet