Anton Leykin Jan Verschelde Ailing Zhao Newton's method with deflation for isolated singularities of polynomial systems. 111-122 2006 359 Theor. Comput. Sci. 1-3 http://dx.doi.org/10.1016/j.tcs.2006.02.018 db/journals/tcs/tcs359.html#LeykinVZ06