Gholampour, C., Maalek, S., G. Ashtiani, M., & Vaseghi, J. "The Experimental Study of Effects of the Degree of Bolt Tightness of MERO Type Jointing System on the Rigidity of the Double Layer Grids" .e21294 , Journal of Civil and Surveying Engineering, 44, 3, 2010, e21294.