Secrets of the English Warbow by H. Soar is a good one, with good measures of two bows, which should be representative , and there is some very nice pictures in Bickerstaffes book.
Plus there is an electronic archive at the official MR website that has some data on the bows.
If I remember correctly, there was going to be published a paper on the bows not so long ago, but I never saw it mentioned on the warbowforum, so I guess it is still in process.