I would like to express my sincere gratitude to my dear colleague and friend, Allan Walstad.  He encouraged me to pursue this project and generously volunteered to examine this book and shared his insight and suggestions.

I also would like to thank my colleagues in other institutions who reviewed this book, pointed out corrections, and gave me suggestions for improving the content.  They are

Christopher Omasits, North Allegheny School District

Paul Ashcraft, Mercyhurst University

John Bradshaw, Indiana University of Pennsylvania

Michael McCracken, Washington & Jefferson College

Gavin Buxton, Robert Morris University.

My thanks also go to my son, Pierce, who patiently helped me clean up the code to fix the formatting messes I kept creating while writing this book online.

This work was made possible by an Open Education Resources Grant awarded by the Office of the  Provost at the University of Pittsburgh.