The Early Medieval World (ebook) by 
Innovation and Creativity in Late Medieval and Early Modern European Cities by See a list of the Auraria Library's books and videos on Gothic cathedrals (various time periods).
See a list of the Auraria Library's books, ebooks, and videos on medieval castles (various time periods).
The Avery Index to Architectural Periodicals offers a comprehensive listing of journal articles on architecture and design, covering topics such as city planning, historic preservation, and interior design, with coverage dating back to the 1930s.
Full text plus abstracts of international peer-reviewed journals, exhibition reviews, trade publications, and museum bulletins. Topics inlcude new artists, contemporary art, archaeology, architecture, art history, film, industrial design, landscape architecture, marketing, photography, pottery, and sculpture.