The Free On-line Dictionary of Computing (30 December 2018):

ALGOL W

    A derivative of ALGOL 60.  It introduced double
   precision, complex numbers, bit strings and dynamic data
   structures.  It is parsed entirely by operator precedence
   and used the call-by-value-result calling convention.

   ["A Contribution to the Development of Algol", N. Wirth, CACM
   9(6):413-431, June 1966].

   ["ALGOL W Implementation", H. Bauer et al, TR CS98, Stanford
   U, 1968].

   (1994-11-24)