1. Ahlf R. E. (1985). “Report of the Ballast and Subgrade Subcommittee of the Association of American Railroads' Track Maintenance Planning Committee.” Association of American Railroads Chicago Ill. Nov.
2. American Railway Engineering Association (AREA). (1984). Manual for railway engineering . Washington D.C.
3. The question of the 125‐ton car;Cerny L. T.;Railway track & structures,1985
4. Track loading fundamentals—Parts 1–7;Clark C. W.;Railway Gazette,1957
5. Committee on Pipeline Crossings of Railroads and Highways. (1964). “Interim specifications for the design of railroads and highways.” ASCE New York N.Y. Jan.