@article{EXMATH_1989__4_3_38333,
     author = {Manuel Gonz\'alez},
     title = {On the index of weakly {Fredholm} operators},
     journal = {Extracta Mathematicae},
     pages = {148},
     publisher = {mathdoc},
     volume = {4},
     number = {3},
     year = {1989},
     language = {en},
     url = {https://geodesic-test.mathdoc.fr/item/EXMATH_1989__4_3_38333/}
}