Columbia subject headings:
Harvard subject headings:
John I, King of Portugal, 1357-1433.
Myth.
Portugal--History--John I, 1385-1433--Philosophy.
Portugal--History--John I, 1385-1433--Sources.
Princeton subject headings:
Portugal--History--Interregnum, 1383-1385.
Portugal--History--John I, 1385-1433.