The appropriate response is the first. You don't make a fiction story appear to be bona fide by including commentaries or references yet you do this when the subject is genuine like history. None of this is about fiction - where you make it up as you compose. At that point, you require activity or occasions to make the book appear to be practical. At the end of the day, a book set in 1944 in England better specify the Second World War or a book set in Germany in 1977 ought to say East and West Germany as independent countries.
