@article{mingoti_rosa_2008,  title={A note on robust and non-robust variogram estimators},  volume={61},  ISSN={0370-4467},  url={https://doi.org/10.1590/S0370-44672008000100014},  DOI={10.1590/S0370-44672008000100014},  number={1},  journal={Rem: Revista Escola de Minas},  publisher={Escola de Minas},  author={Mingoti, Sueli Aparecida and Rosa, Gilmar},  year={2008},  month={Jan},  pages={87–95} }