@InProceedings{	  dix89,
  author	= {J\"{u}rgen Dix},
  title		= {{S}ome {T}endencies in {N}on {M}onotonic {R}easoning: I.
		  {T}he {M}ain {A}pproaches},
  booktitle	= {Proceedings of the 7th Easter Conference on Model-Theory},
  year		= {1989},
  editor	= {Dahn, Bernd I. and Wolter, Helmut},
  pages		= {81--105},
  organization	= {Sektion Mathematik der Humboldt Universit\"{a}t},
  address	= {1086 Berlin, PSF 1297, DDR},
  month		= {April}
}