| Hat in the Ring - Bert Frandsen • libris.ro | 148.50 RON |
| Hat in the Ring: The Birth of American Air Power in the Great War - Bert Frandsen • elefant.ro | 150.99 RON |
Bert Frandsen has a Ph.D. in the history of technology from Auburn University and is an assistant professor of joint warfare studies at the USAF Air Command and Staff College. He lives in Alabama.
