1. Ugo Ascoli wrote part 4 through 6 and Costanzo Ranci wrote part 1 through 3 of this chapter.
2. This methodology togerher with the publication of this book was assisted by the financial support of the FIVOL to whom we owe our sincere thanks. We also owe our deepest gratitude to the individual staff at the FIVOL who assisted us in many administrative ways.