@Criver Would you care to be more specific? History is quite extensive after all (a lot of things happened during WW2) and there are a lot of books out there.
@Doomroar @Korvalus I remember reading it in a Japanese website, I didn't bookmark it so I can't find it anymore. Sorry for causing so much chaos, I didn't think anyone would care. If I manage to find it again, I'll post it here.
@Malikoman NTR makes more money than vanilla, last time I checked NTR was the top selling ero-manga genre, while vanilla was like number 5. Although more people like vanilla, NTR fans are more likely to pay for their hentai. So why not try and make a mainstream NTR manga, it might sell well.