Comma in an introductory clause
December 2, 2007 9:07 PM Subscribe
Do I need the comma in this sentence? "In _Grapes of Europe_, Joe Bloggs reports that grapes are purple." And if so/not, why? I've tried googling adverbial introductory clauses and prepositional introductory clauses, but I can't find a similar example where a work is being introduced.