Won Taek Oh and Adin Richard, Critical Heights of Sloped Unsupported Trenches in Unsaturated Sand. journal = {International Journal of Geotechnical and Geological Engineering}, [online]. World Academy of Science, Engineering and Technology. April 2019, vol. 149(5). 317 - 324 [viewed 20 September 2024]. Available from: https://publications.waset.org/pdf/10010329.