I wish to thank all friends, colleagues and students of Wilhelm for their generous and dedicated assistance in the preparation of this commemorative volume. In particular I thank I give special thanks to my children, Marianna and Bohdan, and to my son-in-law, Norbert Euler, for their great support and assistance in the preparation of the scientific heritage of Wilhelm.

I shall be very grateful to receive all memories and recollections of Wilhelm as the person and the scientist.

With my deepest thanks

Fushchych Ol'ga Ivanivna

Please address all correspondence to the E-mail address:
appmath@imath.kiev.ua
or the postal address:
                    Fushchych Ol'ga Ivanivna
                    Anri-Barbus Street 22/26, apt.73
                    03150 Kyiv
                    Ukraine