Christopher Thomas holds a doctor of philosophy degree (Ph.D.) from Tufts University and is Professor of Math at Massachusetts College of Liberal Arts. His research centered on Geometric Group Theory, exploring places where algebra and geometry meet. He is the author of Calculus Success in 20 minutes a Day (2006) and Trigonometry Success in 20 Minutes a Day (2007).
Barnett Rich (deceased) held a doctor of philosophy degree (Ph.D.) from Columbia University and a doctor of jurisprudence (J.D.) from New York University. He began his professional career at Townsend Harris Hall High School of New York City and was one of the prominent organizers of the High School of Music and Art where he served as the Administrative Assistant. Later he taught at CUNY and Columbia University and held the post of Chairman of Mathematics at Brooklyn Technical High School for 14 years. Among his many achievements are the six degrees he earned and the 23 books that he wrote, among them Schaum's Outlines of Elementary Algebra, Modern Algebra, and Review of Elementary Algebra.