Use the Internet Archive Book link through flickr.com to find images and trace them back to the book.
1. click the magnifying glass (upper right)
2. type in book title or desired image, e.g., "gothic tracery"
3. select a good image and click the link "all the images in the book"
ONLINE
The 19th-century was the great century for line-drawing books on gothic-building details. Many of those pre-1923 books have been scanned and are available online through the archive.org (internet archive). Example, Details of Gothic architecture,1890)
https://archive.org/details/detailsofgothica01coll.
The easiest way to discover these is to find copies in the Duke catalog, library.duke.edu and paste the title into the internet archive books section https://archive.org/details/texts.
see Slick Trick (left) for ways to find simply images.
HARDCOPY
subject heading Architecture, gothic--details
Lilly Reference Library
NA 240
John James. The Ark of God (6 vols.) NA5549.P33 J36 2002
