@article{AL_1969_8_4_a2, author = {S. G. Ivanov}, title = {Standard and dually standard elements of the lattice of subgroups}, journal = {Algebra i logika}, pages = {440--446}, publisher = {mathdoc}, volume = {8}, number = {4}, year = {1969}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/AL_1969_8_4_a2/} }