Tobin's Spirit Guide

Tobin's Spirit Guide by John Horace Tobin is a book that is a compilation of various supernatural occurrences, entities, and facts. The computer software version is hard to find and is very expensive. Egon and Ray refer to it so frequently they may have entire sections memorized. Copies of the book have been shown to be available in hardback, paperback, and electronic media.

History

As Ivo Shandor is mentioned in the tome, it is reasonable to assume Tobin's Spirit Guide was written sometime in the 20th Century. Gozer rituals have been recorded in the book as happening as early as the 1920's so the guide would have to have been published anywhere from 1930-1980.
In The Real Ghostbusters, Egon is shown to carry around a paperback version of the book on assignments. Egon sometimes had Tobin's Spirit Guide on small computer interface devices and later on computer. The latter was noted as being very expensive by Ray, because it probably wasn't popular to which Egon scoffs. It is also shown that the Ghostbusters may not have read every entry, as they often find something new when looking up unknown spirits in the guide. In Extreme Ghostbusters, the team uses Spengler's Spirit Guide, which may borrow material from Tobin's Spirit Guide. It may even be a complete rewrite of Tobin's in Egon's own words. However, the Extreme Team appear to rely more on the internet and checking out books to dig up information on ghosts that they know little about (though a copy of Tobin's can be seen on Egon's desk in the first episode). - http://ghostbusters.wikia.com/wiki/Tobin%27s_Spirit_Guide

Tobin's Spirit Guide often referred to simply as Tobin's is a fictional guide book from the fictional universe of the Ghostbusters franchise. It was first introduced in 1984 in the movie Ghostbusters. After its first reference in Ghostbusters it was referred to several times in other productions of the franchise, e.g. the Ghostbusters video games.
Tobin's provides information about miscellaneous ghosts, spirits, spectres, demons, deities, etc. It is generally used to look up the history, strength and weaknesses of certain supernatural beings. It is quite extensive, providing for example information about the three ghosts of Christmas (Ghost of Christmas past, Ghost of Christmas present, Ghost of Christmas future) and various figures from ancient mythologies, such as Fenris and Surt.
It is unclear when it was written and what the background of the author was. It is only known that the author's name was Tobin (Portram Campbell Tobin)[1] and that it was written some time in the early 20th century.[2]
Tobin's Spirit Guide has become so famous that several non fictional books have been released using the title Tobin's Spirit Guide. - edited from Wikipedia