IEEE P1178 is IEEE Standard 1178-1990, "IEEE Standard for the Scheme Programming Language", published by IEEE in 1991. ISBN 1-55937-125-0. It is now also an ANSI standard. It may be ordered from IEEE by calling 1-800-678-IEEE or 908-981-1393 or writing IEEE Service Center, 445 Hoes Lane, P.O. Box 1331, Piscataway, NJ 08855-1331, and using order number SH14209 ($28 for IEEE members, $40 others).