[1]. Rabia H., “Well Engineering & Construction,” U.K, 2002. ##
[2]. Hossain M. E. and Al-Majed A. A., “Fundamentals of Sustainable Drilling Engineering,” Wiley-Scrivener, 1st ed., Massachusetts, U.S.A, PP.251-319, 2015, DOI: 10.1002/9781119100300.##
[3]. Bourgoyne A. T., Millheim K. K., Chenevert M. E. and Young F. S., “Applied Drilling Engineering,” First Printing, SPE, Society of Petroleum Engineers, Richardson, TX, USA, 1986.##
[4]. Hubbert M. K. and Willis D. G., “Mechanics of hydraulic fracturing,” Journal of Petroleum Technology, pp.153-168, 1957. ##
[5]. Mathews W. R. and Kelly J., “How to predict formation pressure and fracture gradient from electric and sonic logs,” Journal Oil and Gas, Feb.20, 1967. ##
[6]. Eaton B. A., “Fracture gradient prediction and its application in oilfield operations,” JPT, 1353-60, Trans., AIME, 1969. ##
[7]. Anderson, R. A., Ingram, D. S. and Zanier, A. M., “Determining fracture pressure gradients drom well logs,” Journal of Petroleum Technology, SPE 4135 paper presented, Vol. 25, Issue 11, 1973.##
[8]. Sadiq T. and Nashawi I. S., “Using neural networks for prediction formation fracture gradient,” SPE/Petroleum Society of CIM International Conference on Horizontal Well Technology, Calgary, Alberta, Canada, 2000. ##
[9]. Nashawi I. S. and Malallah A., “Predicting the formation fracture gradient of middle east reservoirs using non-parametric optimal transformation,” SPE, Society of Petroleum Engineers, Middle East Oil & Gas Conference International Exhibition Manama, Bahrain, 12–15 March, 2005.##
[10]. Halomoan B. T., Corina A. N., Arimbawa G. V., Aristya R., Purwito S. and Hardama A. F., “A new approaching method to estimate fracture gradient by correcting mathews-kelly and eaton stress ratio,” Elsevier, Journal of Petroleum Science and Engineering, Vol. 7, pp. 261-267, 2015.##
[11]. Whitley D., “A genetic algorithm tutorial: statistics and computing,” pp. 65–85, DOI: 10.1007/BF00175354, 1994. ##
[12]. Koza J. R., “Survey of genetic algorithms and genetic programming,” International Conference in San Francisco, USA, Nov. 7-9, 1995. ##
[13]. Ferreira C., “Gene expression programming: a new adaptive algorithm for solving problems,” Complex Systems, Vol.13, pp. 87–129, 2001. ##
[14]. Ferreira C., “Gene expression programming (mathematical modeling by an artificial intelligence),” Springer-Verlag Berlin Heidelberg, (Second, revised and extended edition), pp. 55-56, 2006. ##
[15]. Azadpour M. and Shadmanaamen N., “Prediction and modeling the mud weight window using well-logging data at one of the Iranian South gas field,” Journal of Petroleum Research, Vol. 26 , No. 87-2, pp.157-166, 2014. ##
[16]. Eaton B. A., “The equation for geopressure prediction from well logs,” Fall Meeting of the Society of Petroleum Engineers, AIME, 1975.##
[17]. Azadpour M., Manaman N. S., Kadkhodaie-Ilkhchi A. and Sadghipour M. R., “Pore pressure prediction and Mmodeling using well-Logging data in one of the gas fields in South of Iran,” Journal of Petroleum Science and Engineering, Vol. 128, pp. 15-23 pp.16-18, April 2015.##
[18]. Atashbari V. and Tingay M. R., “Pore pressure prediction in carbonate reservoirs,” SPE Latin America and Caribbean Petroleum Engineering Conference, Mexico City, Mexico, 2012.
[19]. Zhang J., “Pore pressure prediction from well logs: methods, modifications, and new approaches,” Earth-Science Reviews, Vol. 108, pp. 50-63, 2011. ##
[20]. Holt R., Fjaer E. and Rzayev E., “P-and S-wave velocities in shales: experiments and a model,” 6th North America Rock Mechanics Symposium (NARMS), Gulf Rocks, 2004. ##
[21]. Hughes B., “Formation pressure evaluation,” Houston, USA, 1993. ##