@article{Back_1988,
    doi = {10.1007/bf00291051},
    url = {https://doi.org/10.1007%2Fbf00291051},
    year = {1988},
    month = {aug},
    publisher = {Springer Science and Business Media {LLC}},
    volume = {25},
    number = {6},
    pages = {593--624},
    author = {R. J. R. Back},
    title = {A calculus of refinements for program derivations},
    journal = {Acta Informatica}
}

@article{Back_1988, doi = {10.1007/bf00291051}, url = {https://doi.org/10.1007%2Fbf00291051}, year = {1988}, month = {aug}, publisher = {Springer Science and Business Media {LLC}}, volume = {25}, number = {6}, pages = {593--624}, author = {R. J. R. Back}, title = {A calculus of refinements for program derivations}, journal = {Acta Informatica} }