@article{articlef48d1c19,
title   = {A Perron theorem for the existence of invariant subspaces},
author = {Fusco, Giorgio and Oliva, Waldyr Muniz},
year = {1991},
doi = {10.1007/BF01764120},
journal   = {Annali di Matematica Pura Ed Applicata, (Iv)}
}