@article{10_4007_annals_2007_165_943,
     author = {Daniel Dugger and Daniel C. Isaksen},
     title = {The {Hopf} condition for bilinear forms over arbitrary fields},
     journal = {Annals of mathematics},
     pages = {943--964},
     publisher = {mathdoc},
     volume = {165},
     number = {3},
     year = {2007},
     doi = {10.4007/annals.2007.165.943},
     mrnumber = {2335798},
     zbl = {2335798},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4007/annals.2007.165.943/}
}