Cita APA (7th ed.)

Maps.com (Firm) & ebrary, Inc. (1999). U.S. population change, 1950-1970. Maps.com.

Cita Chicago (17th ed.)

Maps.com (Firm) i Inc ebrary. U.S. Population Change, 1950-1970. [S.l.]: Maps.com, 1999.

Cita MLA (9th ed.)

Maps.com (Firm) i Inc ebrary. U.S. Population Change, 1950-1970. Maps.com, 1999.