References for Willem De Sitter

  1. Biography in Encyclopaedia Britannica. [Available on the Web]

Books:

  1. P Kerszberg, The invented universe : the Einstein-De Sitter controversy (1916-17) and the rise of relativistic cosmology (Oxford, 1989).

December 1996

MacTutor History of Mathematics
[http://www-history.mcs.st-andrews.ac.uk/References/Sitter.html]