The Operation of the English navigation system in colonial Pennsylvania 1681-1750 a case study - Adolf, Leonard Allen, 1927- (Ann Arbor, Mich. : University Microfilms International, 1953)
Thesis (Ph.D.) - University of Washington, 1953.
Keywords: Merchant marine -- United Kingdom -- History -- 17th century; Merchant marine -- United Kingdom -- History -- 18th century; Merchant marine -- United States -- History -- 17th century; Merchant marine -- United States -- History -- 18th century