%0 Journal Article %A I. A. Vakarchuk %T Irreducible cluster expansion for the logarithm of the $s$-particle density matrix of a many-boson system %J Teoretičeskaâ i matematičeskaâ fizika %D 1977 %P 247-261 %V 32 %N 2 %U http://geodesic.mathdoc.fr/item/TMF_1977_32_2_a7/ %G ru %F TMF_1977_32_2_a7