Images of an architect's work can often be found in print books and periodicals. It's worth taking the time to browse through relevant literature to find illustrations.
You can also conduct an Advanced Search in LibrarySearch to add the term "pictorial works" to your search. For example, you can search for "brutalism" AND "pictorial works." Your search results should only include resources that include illustrations. Of course you will find illustrations in resources not assigned the "pictorial works" subject heading, but this is a strategy for narrowing searches that are yielding too many results.
Search these databases with keywords like architects, building names, styles, and locations.
The listed recommended resources usually provide reliable information along with images. For instance, Artstor displays the image source information next to an image of the building: