Acknowledgements The authors wish to express their gratitude to the following individuals for their valuable contributions towards this book: Juha Arrasvuori, Sam Bucolo, Gunner Danneels, Jim Edwards, Anna Hakala, Jussi Holopainen, Jyri Huopaniemi, Quinn Jacobson, Matti Karlsson, Imre Kiss, Hannu Korhonen, Sanna Korpi, Timo Koskinen, Markku Laitkorpi, Ora Lassila, Kari Laurila, Jaakko Lehikoinen, Aaron Marcus, Jouka Mattila, Joe McCarthy, Hannu Nieminen, Marja Niska, Tero Ojanperä, Dana Pavel, David Racz, Erika Reponen, Mika Röykkee, Larry Rudolph, Risto Sarvas, Mirjana Spasojevic, David G. Stork, Toni Strandell, and Kai Willner. Special thanks must go to Tero Hakala for providing and editing much of the photographic material in this book, to Juha Kaario for jointly developing the GEMS model, and to Jussi Impiö for vividly portraying the personas. In addition, the authors would like to thank their families for their support: Tiina, Anniina and Eemeli; Jonna, Anni and Chili (woof); Marja, Petteri, and Valtteri; Annu and Aamu. We wish to thank the staff of our publisher for smooth collaboration: Birgit Gruber, Sarah Hinton, Richard Davies, and Rowan January at John Wiley & Sons. No animals were harmed during the making of this book, but our laptops did receive much punishment. Rest in pieces. Juha Lehikoinen Antti Aaltonen Pertti Huuskonen Ilkka Salminen Tampere, Finland