sentences:  John W. Dower, Sadao Asada, and Roger Dingman credited Hata for the key role he played in producing the multivolume project, which began to be published in 1975, and deemed it the best work of scholarship on the occupation produced until that point.In 1993 Hata wrote a two-volume work on controversial incidents in modern Japanese history, entitled "Shōwashi no nazo wo ou" ("Chasing the Riddles of Showa History"), which was awarded the Kikuchi Kan Prize.Hata co-wrote two books with Yasuho Izawa on Japanese fighter aces of World War II, both of which were described by historians as the definitive treatments of the subject.