http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Calibration frequency for skid measurement systems
prepared by J. Neuhardt, E. A. Whitehurst, M. Gallogly.
Prepared by Research Foundation, Ohio State University, Transplex/OSU report number 156.
Report - Federal Highway Administration ; FHWA-TS-78-224