Merchant vessels of the United States...(including yachts and certain government vessels). - U. S. Bureau of Statistics (Treasury Dept.); U. S. Bureau of navigation (Tresury dept); U. S. Bureau of navigation (Dept. of Commerce and labor); U. S. Bureau of navigation (Dept. of Commerce); U. S. Bureau of marine inspection and navigation (U. S. Gov't Printing Office, 1946)