?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.au=Sigmund%2C+K.&rft.aulast=Sigmund&rft.aufirst=K.&rft.date=1995&rft.isbn=978-94-017-3327-4&rft.title=Hans+Hahn+and+the+foundational+debate&rft.btitle=The+Foundational+Debate+Complexity+and+Constructivity+in+Mathematics+and+Physics&rft.genre=bookitem