M.-L. · Marita Ludwig · Marty Litke
| title | ISBN-13 (ISBN-10) | year of publication |
|---|---|---|
| Pi & The English Alphabet Vol. 1 | 978-1-4944-7797-4 (1-4944-7797-1) | 2014 |
| Pi & The English Alphabet, Vol. 1 | 978-1-4783-7663-7 (1-4783-7663-5) | 2012 |
| Pi - The Great Work | 978-1-4664-9748-1 (1-4664-9748-3) | 2011 |