@article{10_21136_MB_2021_0010_20,
     author = {Souilah, Khalid},
     title = {Generalized quadratic operators and perturbations},
     journal = {Mathematica Bohemica},
     pages = {51--63},
     publisher = {mathdoc},
     volume = {147},
     number = {1},
     year = {2022},
     doi = {10.21136/MB.2021.0010-20},
     mrnumber = {4387468},
     zbl = {07547241},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/MB.2021.0010-20/}
}