@book{MSMF_1989_2_37__1_0,
     author = {Kunyavskij, B. Eh. and Skorobogatov, A. N. and Tsfasman, M. A.},
     title = {Del {Pezzo} surfaces of degree four},
     series = {M\'emoires de la Soci\'et\'e Math\'ematique de France},
     publisher = {Soci\'et\'e math\'ematique de France},
     number = {37},
     year = {1989},
     doi = {10.24033/msmf.338},
     zbl = {0705.14039},
     language = {en},
     url = {http://archive.numdam.org/item/MSMF_1989_2_37__1_0/}
}