@techreport(nguyen00RB, 
  author      = {Linh Anh Nguyen},
  title       = {Clausal Tableau Systems and Space Bounds for 
                 the Modal Logics {K, KD, T}, 
                 {KB, KDB}, and {B}},
  institution = {Institute of Informatics, University of Warsaw}, 
  number      = {TR 00-01(261)}, 
  year        = 2000)