Wessel Ebersohn is the author of this book. Klara's Visitors is no longer an easy book to find. This is due to it being a fictional diary based on Hitler's life but when it was first published the author tried to pass it off as a legitimate historical source of information.
Even though it's fictional it is highly entertaining. The book starts when Hitler is roughly six years old and all the entries early on contain poor spelling and grammer but as the book progresses the structure of the writing becomes more sophisticated. The book starts from when he was a child and ends prior to him becoming dictator of Germany.
The book has no real plot, the basic premise of this diary is that Hitler has one testicle, he has erection problems, he can only get sex off of his cousin who is a prostitute, he wants to do his niece yet she refuses to allow him to do her and the rest of the book is Hitlers ramblings.
If you can find a copy make sure to pick it up, it's a great comical read.