1. 1. A. Meneely, B. Smith, and L. Williams, “Validating software metrics,” ACM Trans. Softw. Eng. Methodol., 2012.
   2. G. O’Regan, “Software Metrics Software Metrics,” 2014, pp. 151–183.
   3. K. P. Srinivasan and T. Devi, “Software Metrics Validation Methodologies in Software Engineering,” Int. J. Softw. Eng. Appl., vol. 5, no. 6, pp. 87–102, 2014.
   4. W. Itzfeldt, “Quality metrics for software management and engineering,” in Managing Complexity in Software Engineering, 2011, pp. 127–152.
   5. K. Mordal, N. Anquetil, J. Laval, A. Serebrenik, B. Vasilescu, and S. Ducasse, “Software quality metrics aggregation in industry,” in Journal of software: Evolution and Process, 2013, vol. 25, no. 10, pp. 1117– 1135. 
   6. C. Symons, “metrics Software Industry Performance,” IEEE Softw., vol. 27, no. 6, pp. 66–72, 2010.