Atanu Sengupta Tapan Kumar Pal Debjani Chakraborty Interpretation of inequality constraints involving interval coefficients and a solution to interval linear programming. 129-138 2001 119 Fuzzy Sets and Systems 1 http://dx.doi.org/10.1016/S0165-0114(98)00407-2 db/journals/fss/fss119.html#SenguptaPC01