@article{offutt1996experimental, author={Offutt, A.J. and Lee, A. and Rothermel, G. and Untch, R.H. and Zapf, C.}, title={An experimental determination of sufficient mutant operators}, journal={ACM Transactions on Software Engineering and Methodology (TOSEM)}, year={1996}, volume={5}, number={2}, pages={99--118} }