Boxplot: quartiles/outliers

Please see
Michael Frigge and David C. Hoaglin and Boris Iglewicz. "Some Implementations of the Boxplot". The 
American Statistician. Vol. 43 (1), February 1989. 50?54. 

They investigate and compared several alternate definitions of the hinges (quartiles)
and conclude that Tukey's definition is best on several criteria.