Based on the Popular Television Serial, a Doctor Who novelisations guide, is a free ebook from Paul Smith of Wonderful Books, available to download from this link –

http://www.wonderfulbook.co.uk/basedon/

It’s an incredibly impressive resource, with a wealth of facts and trivia for all the titles (such as the reprint history of each book, print runs, foreign editions, audiobook adaptations, etc).  Well worth a look.