1. AASHTO (American Association of State Highway and Transportation Officials), 2012. Standard specifications for highway bridges. Sections 4.4.1.3 and 4.4.9. LRFD bridge design specifications, 6th Ed., Washington, DC, pp. 45–66.
2. Progressive failure in slopes of overconsolidated plastic clays and clay-shales;Bjerrum;J. Soil Mech. Found. Div.,1967
3. Geotechnical Stress Analysis for Bridge Abutment Design;Bolton,1991
4. Foundation Analysis and Design;Bowles,1988
5. Code of Practice for Earth Retaining Structures, BS 8002;BSI,2001