*[http://www.portraitofdecay.net/www.phillipgraybill.com/ www.phillipgraybill.com c. 2010] (contains more Ghosts imagery than his current website)
*[http://www.portraitofdecay.net/www.graybillstudio.com/ www.graybillstudio.com c. 2010] (contains unused commissioned NIN photography)
*[http://www.flickr.com/photos/nineinchnails/sets/72157604051114463/ Photos from the recording of ''Ghosts I-IV'']
*[https://archive.org/download/nineinchnails_ghosts_I_IV/nin_ghosts_I-IV.pdf ''Ghosts I-IV'' PDF at archive.org]