Cita APA (7th ed.)

Maps.com (Firm) & ebrary, Inc. (2001). Houston area. Maps.com.

Cita Chicago (17th ed.)

Maps.com (Firm) i Inc ebrary. Houston Area. [S.l.]: Maps.com, 2001.

Cita MLA (9th ed.)

Maps.com (Firm) i Inc ebrary. Houston Area. Maps.com, 2001.