@article{Clarke_1975,
    doi = {10.1090/s0002-9947-1975-0367131-6},
    url = {https://doi.org/10.1090%2Fs0002-9947-1975-0367131-6},
    year = {1975},
    publisher = {American Mathematical Society ({AMS})},
    volume = {205},
    pages = {247--247},
    author = {Frank H. Clarke},
    title = {Generalized gradients and applications},
    journal = {Transactions of the American Mathematical Society}
}

@article{Clarke_1975, doi = {10.1090/s0002-9947-1975-0367131-6}, url = {https://doi.org/10.1090%2Fs0002-9947-1975-0367131-6}, year = {1975}, publisher = {American Mathematical Society ({AMS})}, volume = {205}, pages = {247--247}, author = {Frank H. Clarke}, title = {Generalized gradients and applications}, journal = {Transactions of the American Mathematical Society} }