@article(nguyen01B5SL, 
  author  = {Linh Anh Nguyen},
  title   = {Analytic Tableau Systems and Interpolation 
             for the Modal Logics {KB, KDB, K5, KD5}},
  journal = {Studia Logica},
  year    = 2001,
  pages   = {41-57},
  volume  = 69,
  number  = 1)