APA (7th ed.) Citation

Duffy. (1974). The army of Frederick the Great. David and Charles.

Chicago Style (17th ed.) Citation

Duffy. The Army of Frederick the Great. Newton Abbot, [Eng.]: David and Charles, 1974.

MLA (8th ed.) Citation

Duffy. The Army of Frederick the Great. David and Charles, 1974.

Warning: These citations may not always be 100% accurate.