%0 Journal Article %A E. V. Ferapontov %T Several conjectures and results in the theory of integrable Hamiltonian systems of hydrodynamic type, which do not possess Riemann invariants %J Teoretičeskaâ i matematičeskaâ fizika %D 1994 %P 257-262 %V 99 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/TMF_1994_99_2_a11/ %G en %F TMF_1994_99_2_a11