@incollection{Brock_Nannestad_2010,
    doi = {10.1007/978-3-642-16242-8_12},
    url = {https://doi.org/10.1007%2F978-3-642-16242-8_12},
    year = {2010},
    publisher = {Springer Berlin Heidelberg},
    pages = {157--171},
    author = {Taus Brock-Nannestad and Carsten Schürmann},
    title = {Focused Natural Deduction},
    booktitle = {Logic for Programming, Artificial Intelligence, and Reasoning}
}

@incollection{Brock_Nannestad_2010, doi = {10.1007/978-3-642-16242-8_12}, url = {https://doi.org/10.1007%2F978-3-642-16242-8_12}, year = {2010}, publisher = {Springer Berlin Heidelberg}, pages = {157--171}, author = {Taus Brock-Nannestad and Carsten Schürmann}, title = {Focused Natural Deduction}, booktitle = {Logic for Programming, Artificial Intelligence, and Reasoning} }