@article{IM2_2011_75_2_a5,
     author = {V. A. Krasnov},
     title = {Real four-dimensional biquadrics},
     journal = {Izvestiya. Mathematics },
     pages = {371--394},
     publisher = {mathdoc},
     volume = {75},
     number = {2},
     year = {2011},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_2011_75_2_a5/}
}