| title | ISBN-13 (ISBN-10) | year of publication |
|---|---|---|
| In the Land of Invented Languages: Adventures in Linguistic Creativity, Madness, and Genius | 978-0-8129-8089-9 (0-8129-8089-1) | 2010 |
| In the Land of Invented Languages: Esperanto Rock Stars, Klingon Poets, Loglan Lovers, and the Mad Dreamers Who Tried to Build A Perfect Language | 978-0-385-52788-0 (0-385-52788-8) | 2009 |