Of course the books ARE EVIDENCE, they written mainly by people who lived in the areas and lost their families and friends.
Of course, they aren't. They don't tell us the number of deaths. No one is contesting whether there was use of atomic bombs.
When they tell that a grand parent has survived the blast and the weeks afterwards but came into hospital 1960 where he was in a special treatment area with dozens of similar cases, and the author visited his grand pa every week for years ... why should anybody doubt that?
So there were "dozens" of deaths in the aftermath of these bombings? We already know there were at least 1900. These stories don't tell us whether there was 1900 or 400k such deaths.
people continued dying till the late 1970s early 80s
People will continue to die until there are no more people. Again, you don't seem to understand what evidence is.
Since I pity your inability to form a logical argument, I'll give you a freebie. There are other ways to die after the fact from an atomic explosion than radiation.
If you get burned over half your body, that'll hurt your chances of future survival, even if you recover from it. It might even result in higher cancer rates due to the tissue regeneration and healing. Similarly, if you are permanently blinded by the flash from the atomic explosion then that can increase your chances of dying from various sorts of accidents (such as falling).
There should be a lot of people who die from what injuries they suffered from the atomic bomb blasts. They just won't be dying from radiation-caused deaths.
But rather than serious estimates based on actual injuries received, we get the anti-nuke hysteria. The whole point of these ridiculously exaggerated death counts is to scare people now not do a proper accounting of what happened then.