Tretjakova M.I. , Dremin I.M. , Adamovich M.I. , Chernjavskii M.M. , Gershkovich A.M. , Kharlamov S.P. , Larionova V.G. , Volkov E.I. , Yagudina F.R. Clusters and the rapidity interval method. Nuovo Cimento , Vol.33A,N1 , с. P.183-194 , 01.1976