Siegfried Popper died in 1933.
Siegfried Popper was born in 1848.
Albert Popper died in 1889.
Julius Popper died in 1893.
Hans Popper died in 1988.
Erwin Popper died in 1955.
Josef Popper-Lynkeus died in 1921.
David H. Popper died in 2008.
Siegfried Geyer died in 1944.
André Siegfried died in 1959.
Siegfried Jacobsohn died in 1926.
Siegfried Aufhäuser died in 1969.
Siegfried Czapski died in 1907.