R. Ray และผู้แต่งคนอื่นๆ. (2015) Levels of what and how in the Education of Geo-engineering on Problematic Soils. <i>The Geotechnical Engineering Journal of the SEAGS & AGSSEA</i>, <i>46</i>(4), 110-113.R. Ray และผู้แต่งคนอื่นๆ. "Levels of what and how in the Education of Geo-engineering on Problematic Soils". The Geotechnical Engineering Journal of the SEAGS & AGSSEA 46 (2015):110-113.R. Ray และผู้แต่งคนอื่นๆ. Levels of what and how in the Education of Geo-engineering on Problematic Soils. Southeast Asian Geotechnical Society:ม.ป.ท. 2015.