@article{Apt_2019,
    doi = {10.1007/s00165-019-00501-3},
    url = {https://doi.org/10.1007%2Fs00165-019-00501-3},
    year = {2019},
    month = {dec},
    publisher = {Association for Computing Machinery ({ACM})},
    volume = {31},
    number = {6},
    pages = {751--807},
    author = {Krzysztof R. Apt and Ernst-Rüdiger Olderog},
    title = {Fifty years of Hoare's logic},
    journal = {Formal Aspects of Computing}
}

@article{Apt_2019, doi = {10.1007/s00165-019-00501-3}, url = {https://doi.org/10.1007%2Fs00165-019-00501-3}, year = {2019}, month = {dec}, publisher = {Association for Computing Machinery ({ACM})}, volume = {31}, number = {6}, pages = {751--807}, author = {Krzysztof R. Apt and Ernst-Rüdiger Olderog}, title = {Fifty years of Hoare's logic}, journal = {Formal Aspects of Computing} }