[Friedrich Engels and natural science (on the 150th anniversary of his birth)].
D005197:Famous Persons; D005858:Germany; D049672:History, 19th Century; D010684:Philosophy / Q000266:history; D012586:Science / Q000266:history*; D012950:Socialism / Q000266:history
Fridrikh Engel's i estestvoznanie (k 150-letiiu so dnia rozhdeniia)