Otani, Shunsuke. “Emergency Guideline for Classification of Risk Levels of Earthquake Damaged Reinforced Concrete Buildings”. Bulletin of the New Zealand Society for Earthquake Engineering 21, no. 4 (December 31, 1988): 279-287. Accessed February 27, 2021. https://bulletin.nzsee.org.nz/index.php/bnzsee/article/view/794.