@techreport{DFN98:tr,
author = {J\"{u}rgen Dix and Ulrich Furbach and Ilkka Niemel\"{a}},
institution = {Universit{\"a}t Koblenz-Landau},
month = {August},
note = {Available at \url{http://www.uni-koblenz.de/fb4/publikationen/gelbereihe/}},
number = {20--98},
title = {Nonmonotonic {R}easoning: {T}owards {E}fficient {C}alculi and {I}mplementations},
type = {Fach\-be\-richt Informatik},
year = {1998},
}