O'Neil, B. H. S. J. (1977). Castles: An introduction to the castles of England and Wales ; an illustrated guide .. (3. impr.). HMSO.
Chicago Style (17th ed.) CitationO'Neil, B. H. St. J. Castles: An Introduction to the Castles of England and Wales ; an Illustrated Guide .. 3. impr. London: HMSO, 1977.
MLA (9th ed.) CitationO'Neil, B. H. St. J. Castles: An Introduction to the Castles of England and Wales ; an Illustrated Guide .. 3. impr. HMSO, 1977.
Warning: These citations may not always be 100% accurate.