Other
The Active Eye in Architecture: Birth of a Column
A detailed study of the column, with some reference to its use in Renaissance architecture. Part of an online book about architecture by an amateur for amateurs.
archKIDecture
Arch Ki Decture: Quoin, Defined and Illustrated
The "Word of the Week" from ArchKIDecture, a teacher-created site that encourages awareness of human-built environments, defines the term "quoin."
Curated OER
Image of a Quoin
The "Word of the Week" from ArchKIDecture, a teacher-created site that encourages awareness of human-built environments, defines the term "quoin."