I remember when I was a child (probably about 40 years ago), I read some story in a Russian book (I think its original language was Russian).
The story is as follows: a man read some documentary book about WW2, but it wasn't the same WW2 which we know. It had other events, other names, and another Nazi leader (not Hitler).
And he thought that if he could go to that time and kill this leader, he could save a lot of lives. Then he fell asleep and transferred to that time. He managed to meet this leader and kill him.
Then he woke up at home, took the same book and saw that events changed. WW2 now is the same as we know, and the Nazi leader was Hitler.
It was in a book containing science fiction stories by different authors (for example, I remember another story, where a man could use electricity instead of food and became very strong). This story (which I'm looking for) is short (2-3 pages).
To kill the Nazi leader (before they took power) the man came to one meeting and after the meeting asked the leader for a private conversation and strangled him.
When he was in an old German (or maybe Austrian) city, he hired some man with a mustache to help with his luggage and by mistake gave him a very big banknote (because he was not familiar with local currency). This mustachioed man took the money and disappeared very fast.
When the protagonist returned to his time, he recalled his face and understood who he was. Last sentence in this story: "What was his name? Schicklgruber? Hitler!"
I'd like to find this story. It's probably around the 1970s and in the Russian language.