@article{Gretz_2014,
    doi = {10.1016/j.peva.2013.11.004},
    url = {https://doi.org/10.1016%2Fj.peva.2013.11.004},
    year = {2014},
    month = {mar},
    publisher = {Elsevier {BV}},
    volume = {73},
    pages = {110--132},
    author = {Friedrich Gretz and Joost-Pieter Katoen and Annabelle McIver},
    title = {Operational versus weakest pre-expectation semantics for the probabilistic guarded command language},
    journal = {Performance Evaluation}
}

@article{Gretz_2014, doi = {10.1016/j.peva.2013.11.004}, url = {https://doi.org/10.1016%2Fj.peva.2013.11.004}, year = {2014}, month = {mar}, publisher = {Elsevier {BV}}, volume = {73}, pages = {110--132}, author = {Friedrich Gretz and Joost-Pieter Katoen and Annabelle McIver}, title = {Operational versus weakest pre-expectation semantics for the probabilistic guarded command language}, journal = {Performance Evaluation} }