It has been quite some time ever since the Russian forum has been active.

Now here is something pretty suprising and yet very little infomation is known about it - about a man called Pugachev.

And here are two links which offer"ed" such interesting coins

David Coins - 1 fantasy ruble

5 fantasy kopek

From Romanov Empire -

"Rare Outstanding copper fantacy 5 kopeks of period of Catherine the Great with portrait of the Impostor White Tsar Peter III Fedorovich named Emelian Pugachev - in Cossack General uniform. I hope you remember Alexander Pushkin and his novel Captain daughter. So Catherine the Great issued the order to capture Emelian Pugachev and he finally was captured anf then executed. "

From davidcoins.com -

"Pugachev was a commoner, who declared himself a royalty and spearheaded a rebellion of Cossack army against Ekaterina II (1762 - 1796)

EMILIAN IVANOVICH PUGACHEV was a Don Cossack; he had fought in several wars. In the autumn of 1773 he lead the Ural Cossacks in a revolt which soon was to spread into the Volga basin. He later claimed to be Peter III., the deceased husband of Catherine the Great.

At that time, Russia was at war with the Ottoman Empire, the Russian troops thus had been moved from the area where the rebellion broke out; they were concentrated on the front to the Ottoman Empire. In Russia there was widespread dissatisfaction. "

I wonder if there are any numismatic books about these coins... I rarely heard of such coins, not even in major auctions... pretty interesting

I remember that name from my Russian studies. According to Russian historian Riasanovsky, Pugachev inspired a revolt (deemed popular among the peasantry) against the established order, though was not much of a leader himself.
However, the revolt gained control in many territories from the Ural to the Volga. After he declared himself Emperor, he set up an imitation chancellery (among other things). He ended up being caught, tortured, and executed.

From what I recall, if his movement had had better organization and a plan, it had the potential to achieve something more, because there were loads of dissatisfied peasants, and the military was busy with Turkey.

Those coins are nothing but rubbish, even worse than copies. Pugatschev didn't mint any coins during the revolt. There are no numismatic books about these since they aren't numismatic items.