^U.S. Geological Survey Geographic Names Information System: Crocker Township, Polk County, Iowa
^The History of Polk County, Iowa: Containing a History of the County, Its Cities, Towns, &c. Union Historical Company. 1880. pp. 638.
^Company, Chicago and North Western Railway (1908). A History of the Origin of the Place Names Connected with the Chicago & North Western and Chicago, St. Paul, Minneapolis & Omaha Railways. p. 61.