@article{AGT_2020_20_6_a4,
     author = {Wierstra, Felix},
     title = {\ensuremath{\mathscr{E}}n{\textendash}Hopf invariants},
     journal = {Algebraic and Geometric Topology},
     pages = {2905--2956},
     year = {2020},
     volume = {20},
     number = {6},
     url = {http://geodesic.mathdoc.fr/item/AGT_2020_20_6_a4/}
}