Books - I appear to have 2. The larger one is "Jacques Henri Lartigue Photographer" edited by Vicki Goldberg, ISBN 0-500-54226-0. This has all the best-known shots including the lady with the vast fox fur walking her dog. It also has a number of interesting shots showing a bold use of the panoramic format (I think JHL had a stereo camera which had the option of shooting single-shot panoramas as well).
The other book is called "Boy With A Camera - The Story of Jacques Henri Lartigue" by John Cecil, ISBN 1-85793-600-0. This is far less comprehensive and the repro quality is not as good, but it contains some great shots of family activities such as half a dozen people testing their (self-built) amphibious bicycle in their swimming pool, another family member testing his self-designed inflatable rubber trousers, also in the pool, and the quite well-known shot of a female family member taking a flying leap down a stone staircase to allow JHL to practise his speed photography technique. Never a dull moment chez Lartigue, to be sure!
PS: Amazon is showing these 2 books and others as being in stock!