https://www.lemon64.com/games/details.php?ID=1558
https://www.gamesdatabase.org/game/commodore-64/m-u-l-e-
https://www.gamesdatabase.org/Media/SYSTEM/Commodore_64//Manual/formated/M.U.L.E._-_1983_-_Electronic_Arts.pdf
https://www.c64-wiki.com/wiki/M.U.L.E.
