Between 1951 and 1952 he served as assistant general secretary of the International Astronomical Union, and served as general secretary from 1952 until 1958.
Pieter Bruegel the Elder | Pieter Brueghel | Pieter Mulier II | Pieter Hintjens | Pieter Wispelwey | Pieter Willem Korthals | Pieter Vreede | Pieter van Vollenhoven | Pieter van Musschenbroek | Pieter Vanderlyn | Pieter Teyler van der Hulst | Pieter Snapper | Pieter Rossouw | Pieter Langendijk | Pieter Kasteleyn | Pieter Hugo | Pieter Feith | Pieter de Ring | Pieter de Hooch | Pieter Bourke | Pieter Bleeker | Pieter Aertsen | Pieter Zeeman | Pieter van der Hulst | Pieter van den Hoogenband | Pieter Seelaar | Pieter Rijke | Pieter Paulus | Pieter Nuyts | Pieter Nooten |