I thought it was "L'enfer, c'est les enfants"? (Well, that's exhausted my pseudo-French for the day....)
I could probably arrange to have the cards translated into Chinese. But I've found that tossing a few jelly cups towards the kids tends to quiet them down. Asian markets stock them. I'm assuming there are Asian markets in Paris....
We don't have screaming kids near us, but we do have a family with several yappy little dogs. (And one big woofer.) Apologies to people who love dogs, but the noise is unreal at times. I've often fantasized about inventing a kind of grenade that one could toss into a yard that would emit a gas that would numb the vocal cords, painlessly and humanely silencing dogs.
Actually, that might work for small children, as well.