@article {MR1177343,
    AUTHOR = {Ward, Thomas B.},
     TITLE = {Almost block independence for the three dot {${\bf Z}\sp 2$}
              dynamical system},
   JOURNAL = {Israel J. Math.},
  FJOURNAL = {Israel Journal of Mathematics},
    VOLUME = {76},
      YEAR = {1991},
    NUMBER = {1-2},
     PAGES = {237--256},
      ISSN = {0021-2172},
     CODEN = {ISJMAP},
   MRCLASS = {28D15},
  MRNUMBER = {MR1177343 (93h:28032)},
MRREVIEWER = {Pawe{\l}Gora},
}