Architecture

I've always been really interested in apartment design, especially the structure and layout inside the building that most people don't see from a bird's eye view. To this end, I really enjoy looking at floor plans, especially large ones that show entire floors of an apartment with all the units, corridors, and common spaces. However, when I search for floor plans using the image search function of search engines, most of the results I get are from rental and real estate websites, and Pinterest, the latter of which almost never includes the source of the image. Are there better places for finding floor plans? Especially the whole-floor floor plans I talked about.