K.H. Goh, S. S. Ng, and K.S. Ho. “Bored Tunnelling Directly below Buildings in Singapore Downtown Line”. Geotechnical Engineering Journal of the SEAGS & AGSSEA 48, no. 2 (June 30, 2017): 45–55. accessed May 13, 2025. https://ph01.tci-thaijo.org/index.php/SEAGS_AGSSEA_Journal/article/view/259085.