Actually better than I thought it would be

History Shorts: Richard III - Cathy Burke

I picked this up for free - the listed price is 1.37 (American).  Despite the fact that numerics are used for the lower numbers (10 instead of ten), this actually a pretty good look at Richard III and does address the major issues in rather neutral language.  (So it isn't terribly pro or anti).  If you are a long time student of the time period, you can give it a miss, but if you are interested or simply want a good overview, this is pretty good.