R. E. Hartwig

Some additive results on Drazin inverses

P. Patrício, R. E. Hartwig, R. Hartwig, 2009, Appl. Math. Comput..

The (2, 2, 0) group inverse problem

P. Patrício, R. E. Hartwig, Pedro Patrício, 2010, Appl. Math. Comput..

Group inverses and Drazin inverses of bidiagonal and triangular Toeqlitz matrices

R. E. Hartwig, J. Shoaf, R. Hartwig, 1977, Journal of the Australian Mathematical Society.

More on the Souriau–Frame Algorithm and the Drazin Inverse

R. E. Hartwig, 1976 .