This book is dedicated to my dearest Vanessa, and to Valentina and Gabriela. Thanks for your love, your support, and your patience.
                                                                                                                               – Carlos

To my dear Elena. Without your encouragement, your love, and your patience, this book would not have been possible.
                                                                                                                            – Christian

To my parents, John and Mercedes, who raised me free of constraints. This will be the first book of many. To my love, Clara, for your unconditional support and infinite patience.
                                                                                                                             –  Keyvan