Columbia subject headings:
Artists--Spain--Correspondence.
Mark, Anthony--Correspondence.
Painters--Spain--Correspondence.
Zaera Claussel, Rossana--Correspondence.
Harvard subject headings:
Marco, Antonio, 1929---Correspondence.
Painters--Spain--Correspondence.
Zaera Clausell, Rossana,--Correspondence.
Princeton subject headings:
Artists--Spain--Correspondence.
Mark, Anthony--Correspondence.
Painters--Spain--Correspondence.
Zaera Claussel, Rossana--Correspondence.