Collectors Weekly, «Antique and Vintage Waterman Pens», http://www.collectorsweekly.com/pens/waterman.
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Victoria Barret, «Best Small Companies: Dropbox», Forbes, October 19, 2011. http://www.forbes.com/forbes/2011/1107/best-companies-11-drew-houston-steve-jobs-ferdowsi-dropbox-barret.html.
