@Adrian, I meant to ask you -- do you know a film from the mid-'80s, I think, about society in a bunker after a nuclear holocaust, which I believe was called Arka? I can't find any trace of it on the internet, but the search isn't helped by the fact that someone inconsiderately make another film of the same name in 2007, which overwhelms the results. It wasn't a particularly brilliant film, but it seems to have vanished without a trace, which is curious. I saw it the same year I saw Yesterday, which is from 1985. But there are references to that film all over the place. It's possible that I've remembered the name of the film wrongly, but I was pretty sure of it.