140 Semi-Magic Knight's Tours

The following image (MKTS.GIF) from MagicTour.free.fr by Guenter Stertenbrink shows 140 unique Semi-Magic Knight's Tours.  These are the only such tours that exist, other than 18 additional Semi-Magic Knight's Tours that are rotations, reflections, or reversals of some of the original 140 tours.
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140 Semi-Magic Knight's Tours - magictour.free.fr/MKTS.GIF Guenter Stertenbrink, August 5, 2003