FROM MY REVIEWS IN EXCELLENCE MAGAZINE:

Tribute to the Turbo was initially planned as a limited series of 1000 numbered books to accompany the limited series of 1000 turbos needed to homologate the 934 and 935.  There had been a battle between those who thought that Porsche could only sell the turbos needed for homologation purposes as loss leaders, and those who were confident that they could be sold at the then astronomical price of $25,000; but only if the car were loaded with lots of perceived value, including in this case a special book.  It became quickly apparent that turbos were selling like crazy and giving a book away was a waste of money.  So the last 500 books were sold separately.  Incidentally, I have never seen an edition in German.  The books were more or less remaindered through Stoddard Imported Cars of $47.50, and once again it took some time to sell all the stocks.  

Tribute had all the qualifications of a prestige book.  It was written by Karl Ludvigsen, considered the best automotive author around, who was researching the factory files for Excellence was Expected during this period.  It had superb color photography and came in a sliver slip jacket.  As with all of the later introduction books, developmental history and photographs of the prototypes about.  Tribute has become an expensive book.