1. 1. tutorialspoint, “SDLC ­ Overview,” Tutorialspoint. 2017, doi: 10.1016/j.chemphyslip.2016.11.006.
   2. J. Broad, “System Development Life Cycle (SDLC),” in Risk Management Framework, 2013.
   3. A. Ghahrai, “Software Development Life Cycle – SDLC Phases,” Test. Excell., 2017.
   4. Tutorialspoint, “SDLC Software Prototype Model,” Tutorialspoint, 2017.
   5. V. Osetskyi, “SDLC Models Explained: Agile, Waterfall, V-Shaped, Iterative, Spiral,” Existek, 2017. .
   6. K. Dowding and B. C. Greene, “Spiral Model,” in Encyclopedia of Power, 2012.
   7. A. Mishra and D. Dubey, “A Comparative Study of Different Software Development Life Cycle Models in Different Scenarios,” Int. J. Adv. Res. Comput. Sci. Manag. Stud., 2013.
   8. S. Malik and C. Nigam, “A Comparative study of Different types of Models in Software Development Life Cycle,” Int. Res. J. Eng. Technol., vol. 4, no. 11, pp. 437–440, 2017.