Start with high-confidence medieval architecture books, then narrow by subgenre or adjacent topics.
Universe of Stone
Philip Ball
Life in a Medieval Castle
Joseph Gies, Frances Gies
The Gothic Image
Emile Male, Dora Nussey
Admiration and Awe
Antonio Urquízar-Herrera, Antonio Urquizar-Herrera
Castles
Charles Stephenson
The Bishop's Palace
Maureen C. Miller
Medieval Art
Marilyn Stokstad
A Short History of the Middle Ages, Fifth Edition
Barbara H. Rosenwein
