APA (7th ed.) Citation

Longford, E. (1974). The Royal House of Windsor. Weidenfeld & Nicolson.

Chicago Style (17th ed.) Citation

Longford, Elizabeth. The Royal House of Windsor. London: Weidenfeld & Nicolson, 1974.

MLA (9th ed.) Citation

Longford, Elizabeth. The Royal House of Windsor. Weidenfeld & Nicolson, 1974.

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