Rodríguez, M., and O. López. “Mathematical Models to Incorporate the in-Plane Flexibility of Slabs in the Seismic Analysis of Reinforced Concrete Buildings”. Rev. Téc. Fac. Ing. Univ. Zulia, Vol. 24, no. 2, 1, http://www.produccioncientifica.luz.edu.ve/index.php/tecnica/article/view/5732.