Translations:OMAS/33/en
- http://www.omas.net/ Official web site, irrelevant for historical informations
- http://www.rickconner.net/penoply/misc.19.html An article with a few historical informations
- http://www.rickconner.net/penspotters/omas.html An article with a few historical informations
- http://www.pennamagazine.com/load_detail.aspx?id=5&nt=stilo Nice article on Duofold-like models
- http://www.pennamagazine.com/load_detail.aspx?id=4&nt=stilo Other article on Duofold-lile models