1. RRL Technical Note No. 93;Mayer F. E.,1966
2. S. F. Brown , and P. S. Pell The potential for a theoretically based approach to flexible pavement design The Queens Highway ACMA. No. 107 October 1976 11- 16
3. Symposium on Road Tests for Pavement Design, .Paper 8;Peattie K. R.,1962