B. T. Iancu and O. T. Ionut, “Numerical Analyses of Plate Loading Test Numerical Analyses of Plate Loading Test,” Buletinul Institutului Politehnic Din IASI Publicat de Universitatea Tehnica, Gheorghe Asachi,” Tomul LV (LIX), Fasc. 1, Sectia Construct II. Arhitectura (Iancu Bogdan Teodoru and Ionut-Ovidiu Toma), 2009, pp. 57-65.
 M. K. Elsamny, M. B. Elsedeek and W. N. Abd Elsamee, “Effect of Depth of Foundation on Modulus of Elasticity ‘Es’ for Cohessionless Soil,” Civil Engineering Researches Magazine of Al-Azhar University, Vol. 32, No. 3, 2010, p. 938.
 M. Aminaton, L. Nima, J. Masoud, Kh. Mehrdad, Kh. Mahdy, A. Payman and D. B. Ali, “Foundation Size Ef fect on Modulus of Subgrade Reaction on Sandy Soils,” The Electronic Journal of Geotechnical Engineering, Vol. 17, 2012, pp. 2523-2530.
 ASTM, “Test Method for Density and Unit Weight of Soil in Place by the Rubber Balloon Method (D2167 94),” In 1995 Annual Book of ASTM Standards, Vol. 4, No. 8, American Society for Testing and Materials, Philadelphia, 1994, pp. 167-170.
 L. S. Ping and L. W. Yang, “Subgrade Reaction and Load-Settlement Characteristics of Gravelly Cobble De posits by Plate-Load Tests,” Canadian geotechnical Jour nal, Vol. 35, No. 5, 1998, pp. 801-810.