@incollection{Murlak_2012,
    doi = {10.1007/978-3-642-32589-2_61},
    url = {https://doi.org/10.1007%2F978-3-642-32589-2_61},
    year = {2012},
    publisher = {Springer Berlin Heidelberg},
    pages = {705--717},
    author = {Filip Murlak and Micha{\l} Ogi{\'{n}}ski and Marcin Przyby{\l}ko},
    title = {Between Tree Patterns and Conjunctive Queries: Is There Tractability beyond Acyclicity?},
    booktitle = {Mathematical Foundations of Computer Science 2012}
}

@incollection{Murlak_2012, doi = {10.1007/978-3-642-32589-2_61}, url = {https://doi.org/10.1007%2F978-3-642-32589-2_61}, year = {2012}, publisher = {Springer Berlin Heidelberg}, pages = {705--717}, author = {Filip Murlak and Micha{\l} Ogi{\'{n}}ski and Marcin Przyby{\l}ko}, title = {Between Tree Patterns and Conjunctive Queries: Is There Tractability beyond Acyclicity?}, booktitle = {Mathematical Foundations of Computer Science 2012} }