Wenzel, Jon. Diminishing Shipyard Resources. Third International Conference on the Technical Aspects of the Preservation of Historic Vessels. April 1997 [16 August 2011]. (原始内容存档于2021-02-04).
Wenzel, Jon. Diminishing Shipyard Resources. Third International Conference on the Technical Aspects of the Preservation of Historic Vessels. April 1997 [16 August 2011]. (原始内容存档于2021-02-04).