The Watchtower Library CD-ROM cites Catholic scholar Edmund J. Fortman's book The Triune God in several places when discusing issues relating to the Trinity. The misuse of Fortman by the WT Society has been documented at a few websites. For example, jwfacts.com compares this quote from Should You Believe in the Trinity? taken from Fortman's book with what Fortman actually wrote:
"Jesuit Fortman states: "The New Testament writers . . . give us no formal or formulated doctrine of the Trinity, no explicit teaching that in one God there are three co-equal divine persons. . . . Nowhere do we find any trinitarian doctrine of three distinct subjects of divine life and activity in the same Godhead."" (ti p.6)
"They give us no formal or formulated doctrine of the Trinity, no explicit teaching that in one God there are three co-equal divine persons. But they do give us an elemental trinitarianism, the data from which such a formal doctrine of the Triune God may be formulated."
In fact, a whole comparison of misquotes from Fortman's book by the Watchtower Society can be read at this site.
On the other hand, in context quotes from Fortman's book on how the early Christians understood the relationship between Father, Son and Holy Spirit can be found here at Freeminds.
Fortman's book has been out of print for over 25 years. For those interested, the first 8 chapters (covering the Patristic period) of Fortman's book are available in PDF format at this filesharing site:
http://www.filesend.net/download.php?
f=0a1711f806e428bcb078d107aab5932e
The file is just under 9 MB, is indexed and fully searchable. With this file, one can verify for oneself the misuse of Fortman's book by the Watchtower Society in its writings against the Trinity.