Maps.com (Firm) & ebrary, Inc. (1999). Principal rivers, roads, and canals, 1840. Maps.com.
Chicago Style (17th ed.) CitationMaps.com (Firm) and Inc ebrary. Principal Rivers, Roads, and Canals, 1840. [S.l.]: Maps.com, 1999.
MLA (9th ed.) CitationMaps.com (Firm) and Inc ebrary. Principal Rivers, Roads, and Canals, 1840. Maps.com, 1999.
Warning: These citations may not always be 100% accurate.