Book Clips
thingiverse
I clip out key chapters from books, and then import that info into my stl design. I modify the sphere's dimensions myself - feel free to change whatever you'd like!
Download Model from thingiverse
With this file you will be able to print Book Clips with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Book Clips.