They don't have a lot of information on Martin Kohe. But it looks like he's part of the Napoleon Hill foundation and he has a couple of co-authors with this book and one of them is W. Clement Stone.

This book has sold over 250,000 copies. One of his main subjects in life was how to deal with discouragement. He has some recordings on this subject but I don't know if you can actually access the information.

He was best known as a author and psychologist.

I have not read this book.