“…When F 1 and F 2 contain all subsets of [m] and [n] respectively, COPIC reduces to the bipartite unconstrained quadratic programming problem [23,47,35,39] studied in the literature by various authors and under different names. Also, when F 1 and F 2 are feasible solutions of generalized upper bound constraints on m and n variables, respectively, COPIC reduces to the bipartite quadratic assignment problem and its variations [21,48]. Most quadratic combinatorial optimization problems can also be viewed as special cases of COPIC, including the quadratic minimum spanning tree problem [4], quadratic set covering problem [5], quadratic travelling salesman problem [37], etc.…”