%0 Journal Article %A A. N. Tyurin %T Local and global invariants of a~four-dimensional pseudo-Riemannian manifold %J Trudy Matematicheskogo Instituta imeni V.A. Steklova %D 1984 %P 205-219 %V 165 %I mathdoc %U http://geodesic.mathdoc.fr/item/TM_1984_165_a15/ %G ru %F TM_1984_165_a15