David Coleman Paul Holland Neil Kaden Virginia Klema Stephen C. Peters A System of Subroutines for Iteratively Reweighted Least Squares Computations. 327-336 1980 6 ACM Trans. Math. Softw. 3 http://doi.acm.org/10.1145/355900.355905 db/journals/toms/toms6.html#ColemanHKKP80