Volga, and some other smaller rivers. A quite exhaustive list is in the English Wikipedia "List of rivers in Russia".
Major tributaries are Kama River and Oka River
the Caspian sea
The Caspian Sea: It has a delta. In Caspian Sea.
The longest draining into the Caspian Sea is the Volga River, 3692 Kms
The Caspian Sea
The Volga River flows into the Caspian Sea
It flows into the Caspian Sea
Rivers flow into the Caspian Sea, they do not flow out of. An example is the Volga River.
The River Volga flows into the Caspian Sea.
Caspian Sea
The Caspian Sea
Caspian Sea