Columbia subject headings:
Authors, German--20th century--Correspondence.
Celan, Paul--Correspondence.
Sachs, Nelly--Correspondence.
Harvard subject headings:
Celan, Paul--Correspondence.
Poets, German--20th century--Correspondence.
Sachs, Nelly--Correspondence.
Princeton subject headings:
Authors, German--20th century--Correspondence.
Celan, Paul--Correspondence.
Sachs, Nelly--Correspondence.