There are some facinating (if somewhat dubiously overprecise) posts on this board:-
http://pub39.ezboard.com/fhuntforplanetxfrm63
This is quite a good summary of the issue, with loads of links (in green), explaining the many aspects of the "mythology":-
http://www.crystalinks.com/nibiru.html
I managed to find Paragon Publishings website, but there are no references to Alien Encounters magazine. Unfortunately after about 12 or 13 issues, it ran out of interesting topics and was cancelled after 26 issues. Paragon now produce DVD, PC, and games console magazines and nothing else. Perhaps they are ashamed of their open-minded past.
This is a very informative site :-
http://www.subversiveelement.com/Planet_X.html
As is this:-
http://xfacts.com/x.htm
Hope this helps
