Volume 1 - Letters from Lost Countries collects Air (DC, 2008 series) #1-5; Volume 2 - Flying Machine collects Air (DC, 2008 series) #6-10; Volume 3 - Pureland collects Air (DC, 2008 series) #11-17; Volume 4 - A History of the Future collects Air (DC, 2008 series) #18-24.