Van Hoeve, Willem-Jan The alldifferent Constraint: A Survey The constraint of difference is known to the constraint programming community since Lauriere introduced Alice [11] in 1978. Since then, several solving strategies have been designed for this constraint. In this paper we give both a practical overview and an abstract comparison of these different strategies. Business;Management 2009-11-01
    https://kilthub.cmu.edu/articles/journal_contribution/The_alldifferent_Constraint_A_Survey/6708308
10.1184/R1/6708308.v1