Bookshelf Speaker or Small Speaker
True Bookshelf Speakers are specifically designed to fit IN a bookcase, either vertically, or horizontally at seated ear level. Depth no more than 11-1/2"; recessed connectors; NO PORTS. (perhaps a front facing port).
IF Vintage, IF Restoration is a consideration, I just renovated a pair of AR-2ax’s (initially: nostalgia for my garage/shop system). They sounded better than all the other small speakers I have. In my office they went, I’m renovating a 2nd pair for the garage/shop. Every thing you need is available.