The publication of this volume was made possible only because of the
dedication of several people. If we omit anyone, it reflects only on our memory and
not on our appreciation of their efforts.
It is a special pleasure for us to acknowledge, among others, Professor Vladimir
Wataghin, who immediately accepted the hard job of finding the copies of
Wataghin's papers, several of which dated from more than 70 years ago. He and
his wife made a very thorough list of all papers, which formed the main document
of our collection.
Our thanks go to :
Maria Fabiana Bezerra Muller, Benedita Secundina Gonçalves Imamura,
Maria Aparecida Gonçalves, Rosana Aparecida Martins, for searching and
finding many of the papers in libraries in Brazil and abroad;
Valdineia Mara Viana, Marcos Abreu Nery, Wagner Luís da Silva, Marcos
de Freitas Vassao Junior, for their patient and accurate job of scanning old
papers, not always in good condition;
Professor Enrico Predazzi, for allowing us the use of his paper in the
Introduction of this volume;
Professor Carlos Henrique de Brito Cruz, Head of the "Gleb Wataghin
Physical Institute" of Unicamp, and his staff, for their constant support,
without which this job would have been much more difficult.