@article{10_4064_sm165_3_4,
     author = {Kyewon Koh Park and Uijung Lee},
     title = {Entropy pairs of $\Bbb Z^2$
and their directional properties},
     journal = {Studia Mathematica},
     pages = {255--274},
     publisher = {mathdoc},
     volume = {165},
     number = {3},
     year = {2004},
     doi = {10.4064/sm165-3-4},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm165-3-4/}
}