Todd works for Bethesda Game Studios which produce the Elder Scrolls games. Not many books on his shelves, but he only needed two for the inspiration for these computer games
One could even argue that the name "Skyrim" is the inverse of "Middle-earth".
Sky = earth rim = Middle
Actually, if I were going to make this comparison, I would make a case for the other order of the terms: mapping “earth” onto “rim” and “middle” onto “sky”. The “earth” part of “Middle-earth” is really “geard” (=yard), meaning ‘enclosure’, which can be compared to the “rim” element of Skyrim (which is a kind of enclosure around a circle). The “middle” part was originally conceived of vertically, situating the realm of humans (middan-geard) as between hell and heaven, which is to say the “sky”. So one could view a “Sky-rim” as the next tier up in vertical space from the “Middle-yard” (>> Middle-earth).