9780575084773 | Orion Pub Co, August 8, 2013, cover price $12.25

9780575083714 | Victor Gollancz, July 24, 2008, cover price $26.95

9780575083721 | Victor Gollancz, October 1, 2008, cover price $32.95 | About this edition: Beneath the cloud cover, in the perpetual half-darkness of the shadows cast by immense sky cities looming overhead, toil a race of people known as Groundlings, who have worked for hundreds of years, farming, hunting, fishing, and sending a tithe from their labors up, in giant elevators, to the sky cities above.

9780575082830 | Victor Gollancz, August 1, 2008, cover price $11.95

9780575078789 | Victor Gollancz, August 1, 2006, cover price $22.95 | About this edition: Az Gabrielson, the wingless boy, is going where none of the Airborn have gone before .

9780575079809 | Victor Gollancz, May 28, 2008, cover price $12.95 | About this edition: Az Gabrielson, the wingless boy, is going where none of the Airborn have gone before .

9781435256163 | Reprint edition (Paw Prints, May 28, 2008), cover price $21.95 | also contains The Fledging of Az Gabrielson: The Clouded World Series Book One | About this edition: Az Gabrielson is one of the Airborn, a people who, with a stretch and a beat of their eight-foot wings, travel effortlessly around and between their cities, perched high above the clouds amidst a life of ease and airy beauty.

9780575080324 | Victor Gollancz, August 16, 2007, cover price $19.95 | About this edition: Sequel to The Fledging of Az Gabrielson.

9780575078796 | Victor Gollancz, August 1, 2006, cover price $19.95 | About this edition: Az is one of the Airborn.