Yeon Hee Park, a ninth-degree black belt, was a member of Korea's national Tae Kwon Do team and the undefeated champion of Tae Kwon Do from 1962 to 1967. He served as vice president of the National Tae Kwon Do Union of the United States, the organization responsible for the selection and training of the U.S. Olympic Tae Kwon Do team. He is currently deputy secretary-general of the Pan American Region of the World Tae Kwon Do Federation and the current world Tae Kwon Do Kukkiwon Adviser. He lives in Demarest, New Jersey. Yeon Hwan Park is a ninth-degree black belt and was the undefeated Korean national champion of Tae Kwon Do from 1971 to 1975. He has taught Tae Kwon Do in the United States since 1980. He has coached the U.S. National Tae Kwon Do team, the U.S. Olympic Tae Kwon Do team, and the U.S. Pan American Games Tae Kwon Do team. He has also served as president of the New York State Tae Kwon Do Association and the secretary-general of the United States Tae Kwon Do Union (USTU). He is the former vice president of the USTU and the publisher of USA Taekwondo Review. Park is a professor and lecturer and has coauthored Black Best Tae Kwon Do and authored Tae Kwon Do: My Like and Philosophy for Facts On File. He is currently the president of the United States Taekwondo Leaders Union (USTLU) and an Overseas Advisory Committee member for the Kukkiwon World Taekwondo Headquarters. He lives in East Meadow, New York. Jon Gerrard graduated with a degree in psychology from Princeton University, where he also served as vice president of the Tae Kwon Do Club. He has worked as an investigator for the New York City Bureau of Child Welfare and as a senior investigator and director of planning for anticrime task forces sponsored by the New York City mayor's office. He has taught martial arts to law enforcement agents for more than 10 years. He is currently a teacher in New York.Park, Yeon Hee is the author of 'Tae Kwon Do', published 2009 under ISBN 9780816073993 and ISBN 0816073996.