Voir la notice de l'article provenant de la source eLibrary of Mathematical Institute of the Serbian Academy of Sciences and Arts
@article{PIM_1991_N_S_50_64_a12, author = {P. G. Todorov}, title = {A {Disproof} of a {Conjecture} of {Robertson} and {Generalizations}}, journal = {Publications de l'Institut Math\'ematique}, pages = {105 }, publisher = {mathdoc}, volume = {_N_S_50}, number = {64}, year = {1991}, language = {en}, url = {http://geodesic.mathdoc.fr/item/PIM_1991_N_S_50_64_a12/} }
P. G. Todorov. A Disproof of a Conjecture of Robertson and Generalizations. Publications de l'Institut Mathématique, _N_S_50 (1991) no. 64, p. 105 . http://geodesic.mathdoc.fr/item/PIM_1991_N_S_50_64_a12/