Christmas operas
... that at least nine Christmas operas have been based on Charles Dickens' A Christmas Carol?
... that at least nine <b id="mwAh4"><a href="./List_of_Christmas_operas" id="mwAh8" rel="mw:WikiLink" title="List of Christmas operas">Christmas operas</a></b> have been based on Charles Dickens' <i id="mwAiA"><a href="./A_Christmas_Carol" id="mwAiE" rel="mw:WikiLink" title="A Christmas Carol">A Christmas Carol</a></i>?