Modifiche

== Riferimenti esterni ==

== Riferimenti esterni ==

* http://www.penhero.com/PenGallery/Sheaffer/SheafferTouchdownEarly.htm

* [http://www.penhero.com/PenGallery/Sheaffer/SheafferTouchdownEarly.htm] Pagina dedicate alle prime Touchdown su Penhero

* http://www.vintagepens.com/Sheaffer_Touchdown_Snorkel.shtml

* [http://www.vintagepens.com/Sheaffer_Touchdown_Snorkel.shtml] Pagina sul sito di David Nishimura su Touchdown e [[Snorkel Pen]]

* http://www.penhero.com/PenGallery/Sheaffer/SheafferTouchdownGuide.htm

* [http://www.penhero.com/PenGallery/Sheaffer/SheafferTouchdownGuide.htm] Pagina dedicata al sistema di caricamento [[Touch Down]] su Penhero

* http://www.rickconner.net/penspotters/sheaffer.snorkel.html

* [https://web.archive.org/web/20160401110127/http://www.rickconner.net/penspotters/sheaffer.snorkel.html] Pagina sul sito dismesso di Penspotters su TM Snorkels e predecessori

== Note ==

== Note ==