Kristianto, A., I. Imran, M. Suarjana, and I. Pane. “Confinement of Reinforced-Concrete Columns With NonCode Compliant Confining Reinforcement Plus Supplemental Pen-Binder”. Journal of Engineering and Technological Sciences, vol. 44, no. 3, Sept. 2013, pp. 220-37, doi:10.5614/itbj.eng.sci.2012.44.3.2.