Columbia subject headings:
Harvard subject headings:
Communists--Wales--Biography.
Roberts, John, 1899-1979.
Soldiers--Spain--Biography
Spain--History--Civil War, 1936-1939--Participation, Welsh.
Spain. Ejército Popular de la República. Brigada Internacional, XV--Biography.
Spain. Ejército Popular de la República. British Battalion--Biography.
Welsh--Spain--History--20th century.
Princeton subject headings:
Communists--Wales--Biography.
Roberts, John, 1899-1979.
Soldiers--Spain--Biography.
Spain--History--Civil War, 1936-1939--Participation, Welsh.
Spain. Ejército. Brigada Internacional, XV--Biography.
Welsh--Spain--History--20th century.