There are many, but one of the most useful is:
This is an important book. Anyone who thinks, talks, or writes, needs it! Since so much is embodied in words, its vital to give close attention to the problems of language, meaning and communication as it relates to things psychological, philosophic, religious and metaphysical. This is what this book accomplishes with great skill. Application of the ideas in this book will clarify and empower your thinking and communication skills.
“Each set of religious abstractions is related, somehow, characterologically, to the person who made them; or: tell me your religion and you tell me what you are.” – Insights for the Age of Aquarius, Gina Cerminara