Entity-Relationship Diagram for a scenario involving Books, Authors and Countries
as far as I can see,

you need two separate link tables as these are unrelated, one for linking many books to many authors, and one for linking many countries to many books.


linkTable Author-Book
idOfAuthor | idOfBook  
 1         | 1          

linkTable2 Book-Country
 idOfBook   | idOfCountry
 1          | 1