Nature never deceives us; it is always we who deceive ourselves.
The Social Contract, Jean Jacques Rousseau
In a book of this scope, many sources were consulted to prepare the tables of data presented in this chapter. Most of the data, however, were based primarily on the information drawn from the Doduco Data Book . I am extremely grateful to the Doduco GmBH for permission to freely use the data in this book. Other sources of data were used when that information was not available in the Doduco book. In addition, some of these sources were also used to check the values presented in the Doduco book: examples ...