1. Nebraska Department of Roads, Awarded Bids Average Unit Prices, January 1998 to December 1998.
2. Nebraska Department of Roads, Awarded Bids Average Unit Prices, January 2003 to December 2003.
3. Nebraska Department of Roads, IHIPMS Data File, Ansley to Mason City, F-2-3 (1014) CN: 60792.
4. Nebraska Department of Roads, IHIPMS Data File, Berwyn to Ansley, S-2-3 (1013) CN: 60894.
5. Nebraska Department of Roads, IHIPMS Data File, David City South, F-15-2 (101) CN: 10138.