"E. K." · E. Klapp · O. Klapp · Orrin Edgar Klapp
Holt McDougal · Transaction Publishers
| title | ISBN-13 (ISBN-10) | year of publication |
|---|---|---|
| Collective Search for Identity | 978-0-03-073105-1 (0-03-073105-4) | 1969 |
| Heroes, Villains, and Fools: The Changing American Character | 978-1-4128-5358-3 (1-4128-5358-3) | 2014 |