https://books.google.com.pa/books?id=aqHdswEACAAJ&hl=it&source=gbs_book_other_versions]]>
https://gallica.bnf.fr/ark:/12148/bpt6k3381098j]]>
]]> J.D.S. Walker]]> https://www.sciencedirect.com/science/article/pii/S135503069872088X]]> S. C. Leung]]> https://www.ojp.gov/ncjrs/virtual-library/abstracts/some-observations-morphology-ball-point-pen-stroke]]> Claire Graydon
Steven J. Strach]]> https://journal.asqde.org/articles/10.69525/jasqde.213]]> ]]> Rivista di Problemi Grafologici]]>
Carla Salmaso]]>