S
[SS78] William J. Sakoda and Michael Sipser. Nondeterminism and the Size of Two Way Finite Automata. In STOC'78, pages 275-286. ACM Press, May 1978. 
@inproceedings{stoc1978-SS,
  author =              {Sakoda, William J. and Sipser, Michael},
  title =               {Nondeterminism and the Size of Two Way Finite
                         Automata},
  booktitle =           {{P}roceedings of the 10th {A}nnual {ACM} {S}ymposium
                         on the {T}heory of {C}omputing ({STOC}'78)},
  acronym =             {{STOC}'78},
  publisher =           {ACM Press},
  pages =               {275-286},
  year =                {1978},
  month =               may,
}
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