@article{10_21136_CMJ_2023_0445_21,
     author = {Burgess, Walter D. and Raphael, Robert M.},
     title = {On extending ${\rm C}^{k}$ functions from an open set to $\mathbb R$ with applications},
     journal = {Czechoslovak Mathematical Journal},
     pages = {487--498},
     publisher = {mathdoc},
     volume = {73},
     number = {2},
     year = {2023},
     doi = {10.21136/CMJ.2023.0445-21},
     mrnumber = {4586906},
     zbl = {07729519},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CMJ.2023.0445-21/}
}