Goh Eng Giap, Sunny, and Noborio Kosuke. “Richards’ Equation: Transition Between Constitutive Equations and the Mechanics of Water Flow in Unsaturated Soil”. Journal of Advanced Research in Applied Mechanics 73, no. 1 (November 7, 2020): 11–19. Accessed July 18, 2024. https://akademiabaru.com/submit/index.php/aram/article/view/1519.