First, a caveat: I make no certifications to the soundness of these booklets - as with the writings of all men, always carefully compare all with Scripture. In the doctrines taught by some of these, we may find agreement… with others… well, it's hard to know what might have been going on to prompt its creation!
It is significant though, that some preacher of the Gospel, was once so passionate about a subject that he sat down to write a pamphlet like these, and then paid (probably) to have it published in a day long before word processors and Amazon. The specific concern may have diminished, but even today we may draw insight from their principles.
Booklets
Note: If anyone retains any sort of claim to the copyright, please alert me and I'll remove it immediately.