@article{MZM_1987_41_5_a10,
     author = {V. A. Alexeev},
     title = {Rationality conditions for three-dimensional varieties with sheaf of {Del} {Pezzo} surfaces of degree~4},
     journal = {Matemati\v{c}eskie zametki},
     pages = {724--730},
     publisher = {mathdoc},
     volume = {41},
     number = {5},
     year = {1987},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1987_41_5_a10/}
}