I have a great-grandmother Elizabeth, daughter of Joseph Hertwick in W. PA. While researching them, I've run across some spelling varieties about which I need advice. Are ALL of these names variations of Hertwick? If not, please, somebody let me know which ones I should NOT include in my searches: Hertweck, Hartwick, Hartweck, Hardwick, Hertwig, Hartwig, Hertrick, Hardwig, Hardrick, or even others? Any advice or direction would be much appreciated. I have a few families documented in case anyone else could use info about them in that area (Bradys Bend and Pittsburgh area).