D
[DKR08] Manfred Droste, Werner Kuich, and George Rahonis. Multi-Valued MSO Logics over Words and Trees. Fundamenta Informaticae 84(13-4):305-327. IOS Press, 2008. 
@article{fundi84(3-4)-DKR,
  author =              {Droste, Manfred and Kuich, Werner and Rahonis,
                         George},
  title =               {Multi-Valued {MSO} Logics over Words and Trees},
  publisher =           {IOS Press},
  journal =             {Fundamenta Informaticae},
  volume =              {84},
  number =              {13-4},
  pages =               {305-327},
  year =                {2008},
}
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