%0 Journal Article %A Sergey Ya. Startsev %T Formal Integrals and Noether Operators of Nonlinear Hyperbolic Partial Differential Systems Admitting a Rich Set of Symmetries %J Symmetry, integrability and geometry: methods and applications %D 2017 %V 13 %U http://geodesic.mathdoc.fr/item/SIGMA_2017_13_a33/ %G en %F SIGMA_2017_13_a33