1. ASCE’s 2013 America’s Report Card for Infrastructure, 2. Local agency pavement Management application guide;Broten,1997
3. Nordic Cooperatio Program,http://nordfou.org/
4. Jackson, N., and Jason Puccinelli. Long-Term Pavement Performance (LTPP) Data Analysis Support: National Pooled Fund study TPF-5 (013)-Effects of Multiple Freeze Cycles and Deep Frost Penetration on Pavement Performance and Cost. No. FHWA-HRT-06-121. 2006.