Problem Child (McGraw-Hill, 1980). ISBN 0-07-029325-2 . ^ a b c d e f Alexander and Ann Shulgin . " LSD ", in TiHKAL ( Berkeley : Transform Press, 1997). ISBN 0-9630096-9-9 . ^ Shulgin, Alexander; Shulgin, Ann (1991). "Burt". PiHKAL (1st ed.). Transform Press. p. 21. ISBN   978-0-9630096-0-9 .