@article{SIGMA_2013_9_a67,
     author = {Kenichi Kondo},
     title = {Ultradiscrete {sine-Gordon} {Equation} over {Symmetrized} {Max-Plus} {Algebra,} and {Noncommutative} {Discrete} and {Ultradiscrete} {sine-Gordon} {Equations}},
     journal = {Symmetry, integrability and geometry: methods and applications},
     year = {2013},
     volume = {9},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SIGMA_2013_9_a67/}
}