Modifiche

* [https://web.archive.org/web/20060323180316/http://www.pennamagazine.com/articolo.php?id=226] Article on [[Duofold]] like models (no data on the affirmed [[Parker]]-[[Omas]] relatio)

* [https://web.archive.org/web/20060323180316/http://www.pennamagazine.com/articolo.php?id=226] Article on [[Duofold]] like models (no data on the affirmed [[Parker]]-[[Omas]] relatio)

* [https://web.archive.org/web/20160708102016/http://rickconner.net/penoply/misc.19.html] Article with some historic info

* [https://web.archive.org/web/20160708102016/http://rickconner.net/penoply/misc.19.html] Article with some historic info

* [https://web.archive.org/web/20160527142137/http://www.rickconner.net:80/penspotters/omas.html] Article with some historic info== Notes ==

* [https://web.archive.org/web/20160527142137/http://www.rickconner.net:80/penspotters/omas.html] Article with some historic info

== Notes ==

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