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Publication Order of Boundary Books
| Boundary | (2006) | Hardcover  Paperback  Kindle |
| Threshold | (2010) | Hardcover  Paperback  Kindle |
| Portal | (2013) | Hardcover  Paperback  Kindle |
Publication Order of Boundary: Castaway Books
| Castaway Planet | (2015) | Hardcover  Paperback  Kindle |
| Castaway Odyssey | (2016) | Hardcover  Paperback  Kindle |
| Castaway Resolution | (2020) | Hardcover  Paperback  Kindle |