@article{Fernau_2002,
    doi = {10.1016/s0304-3975(01)00282-1},
    url = {https://doi.org/10.1016%2Fs0304-3975%2801%2900282-1},
    year = {2002},
    month = {apr},
    publisher = {Elsevier {BV}},
    volume = {276},
    number = {1-2},
    pages = {377--405},
    author = {Henning Fernau and Ralf Stiebe},
    title = {Sequential grammars and automata with valences},
    journal = {Theoretical Computer Science}
}

@article{Fernau_2002, doi = {10.1016/s0304-3975(01)00282-1}, url = {https://doi.org/10.1016%2Fs0304-3975%2801%2900282-1}, year = {2002}, month = {apr}, publisher = {Elsevier {BV}}, volume = {276}, number = {1-2}, pages = {377--405}, author = {Henning Fernau and Ralf Stiebe}, title = {Sequential grammars and automata with valences}, journal = {Theoretical Computer Science} }