You can find a good deal for it on Amazon.com. It's not available in ebook form. If you want to view the original source, try Edwin L. Haislet's book. Haislet's ebook has been republished and can be viewed or purchased from Kirk Lawson's Lulu storefront.

The 1943 US Navel Aviation's Boxing, is a near-verbatim reprint of Haislet's book with several additions. An interesting addition is the chapter on feinting and drawing, clinching and infighting. The book outlines more combinations, and contains more details on the drop-shift, triples, as well as shifts. The photographs are nice, although they advocate a more 'square' stance than I would recommend.