@article{ZNSL_1973_33_a3,
     author = {S. S. Ryshkov},
     title = {On perfect form~$A_n^k$: existence of lattices with non-fundamental simplex of division; existence of perfect forms, which are not reducible in the sense of {Minkowski} to a~form with coefficients},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {65--71},
     publisher = {mathdoc},
     volume = {33},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1973_33_a3/}
}