Chronosport editions launched in 2004 a book series on Formula 1 Legends. I think that the first book was on Ayrton Senna, as it had no reference number in the series, so I tend to consider it the number 1 issue.
I latter bought the Alain Prost and Niki Lauda editions. These books are numbered, Alain's has the number 12 written on the side of the book, while Lauda is listed as number 9.
None of these books has some sort of index on them, so I cannot be sure of what the other titles were. Searching through the web, I do know that there are at least 3 more books, on Fangio, Moss and Ascari.
But even so, there are still 6 books missing. Does anyone know if they were published or is this case of a book series that was never fulfield? Unfortunately, Chronosports seem to have stopped publishing Motorsport books around 2009, and their web-site is WIP since 2007, so no luck there.