"1945-05-02" . . . . . . . "Sikorski Institute" . . . . . . . . "Polish Institute and Sikorski Museum" . . . . . . . . . . . . . "Archival, educational, historical, andmuseological" . . . "Polish Institute and Sikorski Museum" . . . . . . . "Registered charity" . . . . . . . . .