@article{SM_2011_202_11_a5,
     author = {V. I. Tsygankov},
     title = {Equations of $G$-minimal conic bundles},
     journal = {Sbornik. Mathematics},
     pages = {1667--1721},
     publisher = {mathdoc},
     volume = {202},
     number = {11},
     year = {2011},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2011_202_11_a5/}
}