When searching for reference images of architecture, remember to think critically about what keywords you are using.
Some important things to consider when brainstorming what keywords to search for architecture and buildings are building materials, architectural styles, historical periods, and building type (castle, temple, etc.).
Artstor is a digital library of almost two million images in the arts, architecture, design, humanities, and social sciences with a suite of software tools to view, present, and manage images for research and teaching purposes. Artstor’s diverse collections are rights-cleared for education and research, and include Open Access content as well as rare materials not available elsewhere.
Here is select list of subject headings to try searching in the Goldstein Library Catalog. You'll want to try different search terms and strategies as your research develops.
Below is a small selection of books to gather reference images of architecture. Many books on architecture are related to specific geographical or cultural areas. Helpful sections to browse for additional titles on architecture are located in the NAs, NKs, and TAs.