@article{10_4153_S0008414X21000110,
     author = {Dai, Feng and Prymak, Andriy},
     title = {On directional {Whitney} inequality},
     journal = {Canadian journal of mathematics},
     pages = {833--857},
     year = {2022},
     volume = {74},
     number = {3},
     doi = {10.4153/S0008414X21000110},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/S0008414X21000110/}
}