@incollection{Hromkovi__2003,
    doi = {10.1007/3-540-45061-0_36},
    url = {https://doi.org/10.1007%2F3-540-45061-0_36},
    year = {2003},
    publisher = {Springer Berlin Heidelberg},
    pages = {439--451},
    author = {Juraj Hromkovi{\v{c}} and Georg Schnitger},
    title = {Nondeterminism versus Determinism for Two-Way Finite Automata: Generalizations of Sipser's Separation},
    booktitle = {Automata, Languages and Programming}
}

@incollection{Hromkovi__2003, doi = {10.1007/3-540-45061-0_36}, url = {https://doi.org/10.1007%2F3-540-45061-0_36}, year = {2003}, publisher = {Springer Berlin Heidelberg}, pages = {439--451}, author = {Juraj Hromkovi{\v{c}} and Georg Schnitger}, title = {Nondeterminism versus Determinism for Two-Way Finite Automata: Generalizations of Sipser's Separation}, booktitle = {Automata, Languages and Programming} }