American Secret Projects: Fighters and Interceptors 1945-1978 - Tony Buttler

American Secret Projects: Bombers, Attack and Anti - Submarine Aircraft 1945 - 1974 - Tony Buttler

British Secret Projects: Fighters and Bombers 1935-1950 - Tony Buttler

Soviet Secret Projects: Bombers Since 1945 - Tony Buttler & Yefim Gordon

Soviet Secret Projects: Fighters Since 1946 - Tony Buttler & Yefim Gordon

Japanese Secret Projects: Experimental Aircraft of the IJA and IJN 1939-1945 - Edwin M. Dyer

Secret Projects: Flying Wings and Tailless Aircraft - Bill Rose