@article{10_4064_ap_15_1_43_55,
     author = {A. Szybiak},
     title = {On the behaviour of the curvature lines in the neighbourhood of an isolated ombilic point},
     journal = {Annales Polonici Mathematici},
     pages = {43--55},
     publisher = {mathdoc},
     volume = {15},
     number = {1},
     year = {1964},
     doi = {10.4064/ap-15-1-43-55},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/ap-15-1-43-55/}
}