@article{ZNSL_1984_134_a3,
     author = {A. M. Vershik},
     title = {Quadratic forms positive on the cone and quadratic duality},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {59--83},
     year = {1984},
     volume = {134},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1984_134_a3/}
}