@article{SM_1993_74_2_a14,
     author = {S. S. Ryshkov and R. M. Erdahl},
     title = {Dual systems of integral vectors (general questions and applications to the geometry of positive quadratic forms)},
     journal = {Sbornik. Mathematics},
     pages = {541--554},
     publisher = {mathdoc},
     volume = {74},
     number = {2},
     year = {1993},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1993_74_2_a14/}
}