Columbia subject headings:
Harvard subject headings:
Ashby, Thomas, 1874-1931--Art collections--Exhibitions.
Biblioteca apostolica vaticana--Exhibitions.
Drawing, European--Exhibitions.
Rome (Italy)--In art--Exhibitions.
Rome (Italy)--Pictorial works
Rome (Italy)--Pictorial works--Exhibitions.
Rome--In art--Exhibitions.
Watercolor painting, European--Exhibitions.
Princeton subject headings:
Ashby, Thomas, 1874-1931--Art collections--Exhibitions.
Biblioteca apostolica vaticana--Exhibitions.
Rome (Italy)--In art--Exhibitions.