It depends on your subject area. Most disciplines have a style guide that recommends how to cite electronic sources. Your program or department may also require that you use a specific style guide. Please note that most style manuals may not specifically address Electronic Theses or Dissertations.

Online citation and style guides can be found at Virginia Tech Library's Citation and Style Manuals link
http://www.lib.vt.edu/find/eref/toc/citation.htm