Update some references.

[ginac.git] / ginac / utils.h

diff --git a/ginac/utils.h b/ginac/utils.h
index b0f24d92e9d414bce8f643beb2a5383e0498ac94..9514dbbe44e28b93883baed739067d24ae0415fd 100644 (file)
--- a/ginac/utils.h
+++ b/ginac/utils.h
@@ -397,7 +397,7 @@ private:
        // Generates all distinct permutations of a multiset.
        // (Based on Aaron Williams' algorithm 1 from "Loopless Generation of
        // Multiset Permutations using a Constant Number of Variables by Prefix
-       // Shifts." <http://webhome.csc.uvic.ca/~haron/CoolMulti.pdf>)
+       // Shifts." <https://dl.acm.org/doi/pdf/10.5555/1496770.1496877>)
        struct coolmulti {
                // element of singly linked list
                struct element {