"Correspondence regarding an exchange of the institutions’ publications."@en . . . . . . . "5 letters"@en . "WL3000/9/1/1587" . "Peter Freiherr von Wrangell was a West German sociologist working for an institute for opinion poll."@en . "This material has been digitised. Readers should book a reading room terminal to access it."@en . . . "Correspondence with Wrangell, Peter Freiherr von"@en . .