I have also seen Czar as an alternate spelling for Tsar (zar). There usually are dual if not multiple spellings of most words that are transfered from one alphabet to another. I have encountered many alternate spellings for Mayan, Nahuatl, etc. words. The originals were written in pictographs. Some of the strange letter combinations take a lot of practice to pronounce correctly,i.e. "atl" The "tl" is a simultanious t sound with the tip of your tounge on the roof of your mouth while softly and sharply hissing(?). Sorry, that's the best way I know to describe it and it is sadly inadequate. I guess you'll just have to corner me in Ireland for a demonstration.