A comprehensive, online bibliography of Gregory Nazianzen, administered by Andrea Schmidt and Isabelle Isebaert-Cauuet at the Université catholique de Louvain, Institut Orientaliste, Centre d’Études sur Grégoire de Nazianze.  Although the site is not browsable, it can be searched in several categories, including author, title, various keywords, year of publication, and language:

http://nazianzos.fltr.ucl.ac.be/003ComplBiblioEF.htm

The database was updated until 2005, after which updates were presented on a separate page, organized by year, without the possibility of searching them:

http://nazianzos.fltr.ucl.ac.be/003ComplBiblioEF.htm