@article{Redheffer_1972,
    doi = {10.2307/2316263},
    url = {https://doi.org/10.2307%2F2316263},
    year = {1972},
    month = {aug},
    publisher = {{JSTOR}},
    volume = {79},
    number = {7},
    pages = {740},
    author = {R. M. Redheffer},
    title = {The Theorems of Bony and Brezis on Flow-Invariant Sets},
    journal = {The American Mathematical Monthly}
}

@article{Redheffer_1972, doi = {10.2307/2316263}, url = {https://doi.org/10.2307%2F2316263}, year = {1972}, month = {aug}, publisher = {{JSTOR}}, volume = {79}, number = {7}, pages = {740}, author = {R. M. Redheffer}, title = {The Theorems of Bony and Brezis on Flow-Invariant Sets}, journal = {The American Mathematical Monthly} }