@article{RM_1988_43_5_a15, author = {V. L. Ginzburg}, title = {On~closed characteristics of 2-forms}, journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova}, pages = {225--226}, publisher = {mathdoc}, volume = {43}, number = {5}, year = {1988}, language = {en}, url = {http://geodesic.mathdoc.fr/item/RM_1988_43_5_a15/} }