Patrick Amestoy Enseeiht-Irit Timothy A. Davis Iain S. Duff Algorithm 837: AMD, an approximate minimum degree ordering algorithm. 381-388 2004 30 ACM Trans. Math. Softw. 3 http://doi.acm.org/10.1145/1024074.1024081 db/journals/toms/toms30.html#AmestoyEDD04