Columbia subject headings:
Critics--Italy--Correspondence.
De Robertis, Giuseppe, 1888-1963--Correspondence.
Piccioni, Leone--Correspondence.
Harvard subject headings:
Critics--Italy--Correspondence
De Robertis, Giuseppe, 1888-1963--Correspondence.
Piccioni, Leone--Correspondence.
Princeton subject headings:
Critics--Italy--Correspondence.
De Robertis, Giuseppe, 1888-1963--Correspondence.
Piccioni, Leone--Correspondence.