Per Year

 @inproceedings{activity-cscw91,
	Author = {Kuutti, Kari},
	Booktitle = {2nd European Conference on CSCW (ECSCW'91)},
	City = {Amsterdam},
	Editor = {Bannon, Liam J. and Robinson, Mike and Schmidt, Kjeld},
	Pages = {249--264},
	Publisher = {Kluwer Academic Publisher},
	Title = {The Concept of Activity as a Basic Unit of Analysis for {CSCW} Research},
        Url = {http://portal.acm.org/citation.cfm?id=1241929},
	Year = 1991}
 

 @article{fuzzydl-91,
  author    = {Yen, John},
  title     = {Generalizing Term Subsumption Languages to Fuzzy Logic},
  booktitle = {IJCAI},
  year      = 1991,
  pages     = {472--477},
  bibsource = {DBLP, http://dblp.uni-trier.de}
} 

 @inproceedings{rao-bdi91,
	Address = {San Mateo, CA},
	Author = {Rao, Anand S. and Georgeff, Michael P.},
	Booktitle = {2nd International Conference on Principles of Knowledge Representation and Reasoning (KR'91)},
	Editor = {Allen, James F. and Fikes, Richard and Sandewall, Erik},
	Pages = {473--484},
	Publisher = {Morgan Kaufmann Publishers},
	Title = {Modeling Rational Agents within a {BDI} Architecture},
	Year = 1991}
 

 @inproceedings{brooks-ijcai91,
	Address = {San Francisco, CA, USA},
	Author = {Brooks, Rodney A.},
	Booktitle = {12th International Joint Conference on Artificial Intelligence (IJCAI 1991)},
	Editor = {Mylopoulos, John and Reiter, Ray},
	Isbn = {1-55860-160-0},
	Location = {Sidney, Australia},
	Pages = {569--595},
	Publisher = {Morgan Kaufmann Publishers Inc.},
	Title = {Intelligence Without Reason},
	Url = {http://dl.acm.org/citation.cfm?id=1631258},
	Volume = 1,
	Year = 1991} 

 @incollection{norman1991-cognitiveartifacts,
	Author = {Norman, Donald A.},
	Booktitle = {Designing Interaction: Psychology at the Human-Computer Interface},
	Editor = {Carroll, John M.},
	Isbn = {0-521-40056-2},
	Pages = {17--38},
	Publisher = {Cambridge University Press, New York},
	Series = {Cambridge Series On Human-Computer Interaction},
	Title = {Cognitive Artifacts},
	Url = {http://portal.acm.org/citation.cfm?id=120354},
	Year = 1991}