The other night Bill Crider listed a site where you can get free Norbert Davis ebooks. Here's the url http://manybooks.net/authors/davisn.html
For me, Davis is one of the most enjoyable of all the great pulp craftsmen, mostly because he managed to turn the tropes of crime fiction into screwball comedy while simeltaneously supplying some very good mystery stories.
John D. MacDonald wrote a long introduction to Davis' Max Latin stories. He lamented that Davis turned his work toward the slicks after creating such fine material for the pulps. The slicks sounded better than they were in actuality for most pulp writers. Making sales was hit and miss and the limitations on content were severe. MacDonald noted the great range they'd all enjoyed in the pulps and pointed out that Davis had certainly taken advantage of the freedom. All this was moot. David mysteriously committed suicide at age 49.
Here's another site worth looking at, The Mystery*File overview of Davis' career complete with photos and some interesting material on Wittengsetin the great philospher and his appreciation for Davis' stories. http://www.mysteryfile.com/NDavis/Wit.html