These were produced by Adam Fleischer for the third Symposium in, I think, 1984 (I'm basing this on the fact that a trick of Hamman's "Phoenix Four," appears in the third Symposium book).
The Hamman book was produced illegally. In other words, Fleischer requested some tricks for a set of lecture notes that he would produce for Brother Hamman, and then give Hamman the bulk of the money. Once Fleischer procurred the tricks, he sent them to Stephen Minch with the instructions that a book be prepared. Hamman was not aware of this, Minch was not aware that Hamman had not given his consent.
To make matters worse, the title "Seven Deadly Miracles" was chosen.
When Hamman arrived at the convention (I personally witnessed this), he was furious because a book had been published without his consent; he hated the title; and Fleischer tried to force him to take less money than had been agreed upon for both the book and his convention appearance!
Stephen Minch was mortified that he had unwittingly written a book for which Hamman had not given consent.
The whole story is very sad.