Azumanga Daioh: Supplemental LessonsRebel_Raven said:Azuma released more? I gotta dig that up! XD
I did a quick google search for a legal read-online option, and this is what I came up with:
http://www.mangapark.com/manga/azumanga-daioh-supplementary-materials/c1/1
So... there you go. Three more books of Azumanga Daioh set within the existing four.