Mauritania C91

     "The Ankara-Tehran route map of the 20f. value of a 1969 Mauritanian issue marking the London-Sidney Motor Rally is not on Mercator's Projection, so the direction rose incorporated can only apply to a very limited section of the map, even approimately."

D.E.G. Irvine & M. Seshold, Errors in Postage Stamp Design, p. 80.