Dear Evan,

Thanks for your response.

We can distinguish between the actual religious texts (scriptures), and literature about them. The Bhagavad Gita has been described as the best example of the Perennial Philosophy. That would be a long read, but see this pdf:

www.ajol.info/index.php/ujah/article/download/210224/198178

I can easily understand why Armiger would not include Taoism, but I think a case can be made. The classic text the Tao Te Ching is the best resource, but not an obvious a source of Perennialism.

As for related literature, the books I mentioned in my article are a good resource. Huxley's is the easiest read. Traditionalism has been described by Gary Lachman (prolific writer on spirituality and esotericism) as “an extreme form of the Perennial Philosophy”. Despite that Oldmeadow's book is interesting and a good resource, although from memory he focused on four significant figures from the Perennial tradition. Schuon's book is a bit heavy, but he is prolific and remains one of the most significant figures in Perennialism.

Apart from that, an internet search should provide some interesting free material.

Best wishes.