It is listed on the Hal Leonard website the same way. When Volume I is sold separately it is listed as 9 1/2" X 12". this is listed as 9" by 12".There are different stock #'s for this set and the other separate volumes. Here is some of their answer to my questions about this set. I had mentioned the other volumes but they didn't address them. "This is three separate books sold together as a set. Hal Leonard hadn't entered it into the data base they give us until a couple of days ago. They are busy adding descriptions and pictures of items that are missing information in their database. We update ours every week for our suppliers, so the changes should go in there soon. In the meantime, the information you need about this 3-book set is as follows: THE ART OF BAROQUE TRUMPET PLAYING Complete Set of 3 Volumes Series: Schott Publisher: Schott Trumpet Composer: Edward H. Tarr....... ......... This is in English and German. The size is 9 x 12 inches and the total number of pages for all three books is 336. I They claim that I am getting 336 pages. Seems like a free lunch but I have seen it listed at least 3 other sites the same way. Drawbridge was the cheapest.