Joint flight of the Soviet spacecrafts Vostok 3 and Vostok 4 by Andrian Nikolayev and Pavel Popovich.
and Pavel Romanovich Popovich
The two Russian cosmonauts Nikolayev (in spacecraft Vostok 3 flighing from 11 until 15 August 1962) and Popovich (in spacecraft Vostok 4 flighing from 12 until 15 August 1962) participated in the world's first joint space flight.
I zespołowy lot kosmiczny = The first joint space flight.
Nikołajew is the Polish spelling of the Russian Nikolayev.
Popowicz is the Polish spelling of the Russian Popovich.
Soviet space programme