Columbia subject headings:
Harvard subject headings:
Berek, M. (Max), 1886-
Berek, M. (Max), 1886---Criticism and interpretation.
Berek, M. (Max), 1886---Interviews.
Leica camera--History--20th century.
Microscopy--Germany--History--20th century.
Optics--Germany--History--20th century.
Petrographic microscope--Germany--History--20th century.
Physicists--Germany--Biography
Princeton subject headings:
Berek, M. (Max), 1886-
Berek, M. (Max), 1886---Interviews.
Interviews.
Inventors--Germany--Biography.
Leica camera--History--20th century.
Microscopy--History--20th century.
Optics--Germany--History--20th century.