Zahn, F. A., R. Park, M. J. N. Priestley, and H. E. Chapman. 1986. “Development of Design Procedures for the Flexural Strength and Ductility of Reinforced Concrete Bridge Columns”. Bulletin of the New Zealand Society for Earthquake Engineering 19 (3):200-212. https://doi.org/10.5459/bnzsee.19.3.200-212.