Here are some references to get you going, in pseudo-BiBTeX
format.
<br>
<br>
A good survey paper is:
<br>
<br>
  author="C. D. Paice",
  title="Constructing Literature Abstracts by Computer:
         Techniques and Prospects",
  journal="Information Processing and Management",
  year="1990",
  volume="26",
  number="1",
  pages="171--186"
<br>
<br>
This will suggest many other references. For a more theoretical
discussion, see:
<br>
<br>
  author="Sparck Jones, K.",
  title="What might be in a Summary?",
  booktitle="Proceedings of the German Information Retrieval
             Conference",
  year="1993"
<br>
<br>
Particular summarising methods:
<br>
<br>
word-frequency methods:
<br>
<br>
  author="H. P. Luhn",
  title="The Automatic Creation of Literature Abstracts",
  editor="Schultz",
  booktitle="H. P. Luhn: Pioneer of Information Science",
  publisher="Spartan",
  year="1968"
<br>
<br>
  author="S. Williams and K. Preston",
  title="Managing the Information Overload",
  journal="Physics in Business",
  publisher="Institute of Physics",
  year="1994"
<br>
<br>
  (this system -- BT's NetSumm -- can be tried at
     http://www.labs.bt.com/innovate/informat/netsumm/index.htm)
<br>
<br>
  author="E. F. Skorochod'ko",
  title="Adaptive Method of Automatic Abstracting and Indexing",
  booktitle="Information Processing 71",
  year="1971",
  pages="1179-1182"
<br>
<br>
  @techreport
  author="M. Benbrahim and K. Ahmad",
  title="Computer-aided Lexical Cohesion Analysis and Text Abridgement",
  series="Knowledge Processing",
  number="18",
  institution="University of Surrey",
  year="1994"
<br>
<br>
c(l)ue phrase methods:
<br>
<br>
  author="J. E. Rush and R. Salvador and A. Zamora",
  title="Automatic Abstracting and Indexing. {II}. {P}roduction of Indicative
         Abstracts by Application of Contextual Inference and Syntactic
         Coherence Criteria",
  journal="Journal of the American Society for Information Science",
  year="1971",
  month="July",
  pages="260--274"
<br>
<br>
  author="C. D. Paice",
  title="The Automatic Generation of Literature Abstracts: an Approach
         based on the Identification of Self-indicating Phrases",
  booktitle="Information Retrieval Research",
  editor="R. N. Oddy and S. E. Robertson and C. J. van Rijsbergen
          and P. W. Williams",
  year="1981",
  publisher="Butterworths",
  pages="172--191"
<br>
<br>
methods which use domain-knowledge:
<br>
<br>
  author="G. F. DeJong",
  title="An overview of the FRUMP system",
  editor="Lehnert and Ringle",
  booktitle="Strategies for Natural Language Processing",
  publisher="Erlbaum",
  address="Hillsdale HJ",
  year="1982"
<br>
<br>
  @techreport
  author="J. I. Tait",
  title="Automatic Summarizing of {E}nglish Texts",
  number="47",
  note="PhD thesis",
  institution="University of Cambridge Computer Laboratory",
  year="1983"
<br>
<br>
As far as I am aware, there are very few comparative studies.
Here is one:
<br>
<br>
  @techreport
  author="P. Gladwin and S. Pulman and Sparck Jones, K.",
  title="Shallow Processing and Automatic Summarising: a First Study",
  number="223",
  institution="University of Cambridge Computer Laboratory",
  year="1991"
<br>
<br>
You may also be interested in theories of how people summarise
text as they read it, in which case take a look at:
<br>
<br>
  author="T. A. van Dijk and W. Kintsch",
  title="Strategies of Discourse Comprehension",
  publisher="Academic Press",
  address="New York",
  year="1983"
<br>
<br>
  author="W. Kintsch and T. A. van Dijk",
  title="Toward a Model of Text Comprehension and Production",
  journal="Psychologial Review",
  year="1978",
  volume="85",
  number="5",
  pages="363--394"
<br>
<br>
For information about how professional abstracters work, there is
lots of good work by Liddy, for example:
<br>
<br>
  author="E. D. Liddy",
  title="The Discourse-level Structure of Empirical Abstracts: an
         Exploratory Study",
  journal="Information Processing and Management",
  year="1991",
  volume="27",
  number="1",
  pages="55--81"
<br>
<br>
  author="E. D. Liddy and S. Bonzi and J. Katze and E. Oddy",
  title="A Study of Discourse Anaphora in Scientific Abstracts",
  journal="Journal of the American Society for Information Science",
  year="1987",
  volume="38",
  number="4",
  pages="255--261"
<br>
<br>
Richard Tucker [Richard.Tucker@cl.cam.ac.uk]