Columbia subject headings:
Harvard subject headings:
Authors, German--20th century--Correspondence
Lersch, Heinrich, 1889-1936--Correspondence.
Schroeder, Mathias Ludwig, 1904---Correspondence.
Princeton subject headings:
Authors, German--20th century--Correspondence.
Lersch, Heinrich, 1889-1936--Correspondence.
Schroeder, Mathias Ludwig, 1904---Correspondence.