Columbia subject headings:
Christian saints--Netherlands--Biography.
Missionaries--Netherlands--Biography.
Willibrord, Saint, 658?-739.
Harvard subject headings:
Christian saints--Netherlands--Biography.
Missionaries--Netherlands--Biography.
Willibrord, Saint, 658?-739.
Princeton subject headings:
Christian saints--Netherlands--Friesland--Biography.
Friesland (Netherlands)--Church history.
Missionaries--Netherlands--Friesland--Biography.
Willibrord, Saint, 658?-739.