@article{IM2_2013_77_3_a1,
     author = {E. Bayer-Fluckiger and R. Parimala and J-P. Serre},
     title = {Hasse principle for $G$-trace forms},
     journal = {Izvestiya. Mathematics },
     pages = {437--460},
     publisher = {mathdoc},
     volume = {77},
     number = {3},
     year = {2013},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_2013_77_3_a1/}
}