Columbia subject headings:
Art historians--Italy--Correspondence.
Cavalcaselle, G. B. (Giovanni Battista), 1819-1897--Correspondence.
Mugna, Pietro--Correspondence.
Mugna, Pietro.
Harvard subject headings:
Art historians--Italy--19th century--Correspondence.
Cavalcaselle, G. B. (Giovanni Battista), 1819-1897--Correspondence.
Mugna, Pietro--Correspondence.
Princeton subject headings:
Art historians--Italy--Correspondence.
Cavalcaselle, G. B. (Giovanni Battista), 1819-1897--Correspondence.
Mugna, Pietro--Correspondence.
Mugna, Pietro.