@article{MAN_1985__270_182954,
     author = {Yukihiko Namikawa},
     title = {Periods of {Enriques} {Surfaces.}},
     journal = {Mathematische Annalen},
     pages = {201--222},
     year = {1985},
     volume = {270},
     zbl = {0536.14024},
     url = {http://geodesic.mathdoc.fr/item/MAN_1985__270_182954/}
}