@article{10_4153_S0008439520000119,
     author = {Chapman, Adam and McKinnie, Kelly},
     title = {Essential {Dimension,} {Symbol} {Length} and $p$-rank},
     journal = {Canadian mathematical bulletin},
     pages = {882--890},
     year = {2020},
     volume = {63},
     number = {4},
     doi = {10.4153/S0008439520000119},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/S0008439520000119/}
}