1. American Concrete Institute, ACI 228.1R-19, In-Place Methods to Estimate Concrete Strength, Report of ACI Committee 228 on Nondestructive Testing, American Concrete Institute, Farmington Hills, MI, 2019, pp. 48.
2. Highway Materials Engineering, Module VI: Concrete;Hover,1990
3. Highway Materials Engineering, Module VI: Portland Cement Concrete;Hover,2003
4. Highway Materials Engineering, Module VI: Portland Cement Concrete Lab Manual;Hover,2003
5. K.C. Hover, Comparison of Non-Destructive Test Results with Core Strengths Observed in the FHWA Highway Materials Engineering Course, Unpublished presentation to the Transportation Research Board, Washington, 2015.