Abstract
Our results in [4] will be generalized to equations of the form:
∗ This research was supported by the Alexander voil Humboldt Foundation of the Federal Republic of Germany at the Mathematical Institute of the University of Cologne
∗ This research was supported by the Alexander voil Humboldt Foundation of the Federal Republic of Germany at the Mathematical Institute of the University of Cologne
Notes
∗ This research was supported by the Alexander voil Humboldt Foundation of the Federal Republic of Germany at the Mathematical Institute of the University of Cologne