Australian Dictionary of Biography website, viewed 13 November 2013 (Willem Janssen (flourished 1603-1628), mariner, of Amsterdam. Skipper of the small yacht Duyfken. In 1605-06 he took part as her skipper in the first discovery of any part of the Australian coastline when he examined the east coast of the Gulf of Carpentaria from 11°S to 14°S) http://adb.anu.edu.au/biography/janssen-willem-2270