@article{01310578, title = {Caustic of the three-dimensional ellipsoid. (Caustique de la surface ellipso\"\i dale \`a trois dimensions.)}, journal = {Experimental Mathematics}, volume = {8}, year = {1999}, pages = {49-55}, doi = {10.1080/10586458.1999.10504387}, zbl = {0951.53002}, language = {en}, url = {http://dml.mathdoc.fr/item/01310578} }
Joets, Alain; Ribotta, Roland. Caustic of the three-dimensional ellipsoid. (Caustique de la surface ellipsoïdale à trois dimensions.). Experimental Mathematics, Tome 8 (1999) pp. 49-55. doi : 10.1080/10586458.1999.10504387. http://gdmltest.u-ga.fr/item/01310578/