Park, J., Kim, L. H., Nam, S. W. and Yeo, I. (2013). “Performance evaluation of airtightness
                           in concrete tube structures for super-speed train systems.” Magazine of Concrete Research,
                           Vol. 65, No. 9, pp. 535-545.10.1680/macr.12.00161Park, J., Kim, L. H., Nam, S. W.
                           and Yeo, I. (2013). “Performance evaluation of airtightness in concrete tube structures
                           for super-speed train systems.” Magazine of Concrete Research, Vol. 65, No. 9, pp.
                           535-545.
