Berry, R. Stephen. creator etc. text S.l.] John Wiley & Sons Inc 1980 monographic 284 p. 547 BER 0471048291 9780471048442 (hardcover) http://www.amazon.com/exec/obidos/ASIN/0471048445/chopaconline-20 http://www.amazon.com/exec/obidos/ASIN/0471048445/chopaconline-20