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@article{AIHPA_1994__61_1_87_0, author = {W\"unsch, V.}, title = {Huygens' principle on {Petrov} type {N} space-times}, journal = {Annales de l'I.H.P. Physique th\'eorique}, pages = {87--102}, publisher = {Gauthier-Villars}, volume = {61}, number = {1}, year = {1994}, mrnumber = {1303187}, zbl = {0814.53060}, language = {en}, url = {http://geodesic.mathdoc.fr/item/AIHPA_1994__61_1_87_0/} }
Wünsch, V. Huygens' principle on Petrov type N space-times. Annales de l'I.H.P. Physique théorique, Tome 61 (1994) no. 1, pp. 87-102. http://geodesic.mathdoc.fr/item/AIHPA_1994__61_1_87_0/