?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adissertation&rft.au=Taatgen%2C+Niels&rft.aulast=Taatgen&rft.aufirst=Niels&rft.date=June+1999&rft.title=Learning+without+limits%3A+from+problem+solving+towards+a+Unified+Theory+of+Learning&rft.inst=University+of+Groningen%2C+Netherlands