@article{RM_1976_31_5_a5,
     author = {H. Freudenthal},
     title = {The connections between the $E_7$-geometry and the configuration of the 28 double tangents to the curve of order~4},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {62--66},
     publisher = {mathdoc},
     volume = {31},
     number = {5},
     year = {1976},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_1976_31_5_a5/}
}