@article{CRMATH_2003__337_2_89_0,
     author = {Alessandro Perotti},
     title = {A differential criterium for regularity of quaternionic functions},
     journal = {Comptes Rendus. Math\'ematique},
     pages = {89--92},
     publisher = {Elsevier},
     volume = {337},
     number = {2},
     year = {2003},
     doi = {10.1016/S1631-073X(03)00284-X},
     language = {en},
}