On generation of permutations of m out of n items

New algorithms are proposed for generation of (n,m)-permutations, 1≤m≤n. The representation of (n,m)-permutations is derived from m-level iterative decomposition of symmetric permutation group Sn into cosets. The control sequence produced by the generation algorithms appears in lexicographic order while the output sequence is obtained from the control sequence in a linear order. Ranking and unranking schemes for control sequences are given. An implementation of a hardware generator of (n,m)-permutations by means of a cellular interconnection network is described.