Underdesk Book Holder

My desk is always cluttered and I need to organize it. I find myself sketching many print ideas, so the first thing on the list was a place to put my sketchbook that wasn't taking up desk space. This hangs under the desk and allows for me to easily slide my sketchbook in and out as needed. Held in by three screws, but double sided tape, glue, or 3m stripes would work just as well, as this doesn't bear much weight.