12.Ha, G. J., Shin, J. H., Kwak, Y. K., and Kwon, C. S., “Improvement and Evaluation
                           of Structural Performance of Steel Fiber Reinforced Concrete Beams Using Early Age
                           Concrete,” Journal of the Korea institute for Structural Maintenance Inspection, Vol.
                           3, No. 3, 1999, pp. 129-137.
