1. Inconclusive opinions: refuge of the questioned document examiner;Whiting;Journal of Forensic Sciences,1990
2. Handwriting identification vs elimination;Dick,1966
3. How individual are personal writing habits?;Hilton;Journal of Forensic Sciences,1983
4. Scientific Examination of Questioned Documents, revised edition;Hilton,1982
5. Variation, A measure of genuineness;Muehlberger,1982