%0 Journal Article %A A. G. Izergin %A A. R. Its %A V. E. Korepin %A N. A. Slavnov %T The matrix Riemann--Hilbert problem and differential equations for correlation functions of the $XXO$ Heisenberg chain %J Algebra i analiz %D 1994 %P 138-151 %V 6 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/AA_1994_6_2_a4/ %G ru %F AA_1994_6_2_a4