@article{DAN_1957_113_5_a17, author = {G. A. Gurzadyan}, title = {On the structure of planetary nebulae}, journal = {Doklady Akademii Nauk}, pages = {1013--1016}, publisher = {mathdoc}, volume = {113}, number = {5}, year = {1957}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1957_113_5_a17/} }