Are you sitting comfortably? Then I'll begin.
Notes from Wikiquote
BBC web-site - Accessed 25 Jan 2011 | cite book | Note that Frieda Fordham (a psychologist who advised the BBC) has also been credited with coining it.
Quote text and notes from Wikiquote: Julia Lang (page history), available under CC BY-SA 4.0. Source quality and labels are our own summary of what Wikiquote records.