Pieter Hennipman was a Dutch economist, Professor of Economics at the University of Amsterdam, who is considered the "leading Dutch economist of the post-war period."
Pieter Hennipman (1945)
Henri (Hans) Theil was a Dutch econometrician and professor at the Netherlands School of Economics in Rotterdam, known for his contributions to the field of econometrics.
prof. dr. H. Theil, 1966