Use One Content type's field as a reference in another content type's view?
My solutions is    

1. In your Quiz content type remove book_id field , add another field with (each name you want here I named it my_book_id ) select type node reference  for it.

then in views, create a views of content type quiz, create a relation on my_book_id then you can add book title .

2. Another way is using php views field 
create a views with content type quiz, select quiz desire field, then add my_book_id field ,exlude it from dispaly then create php field , in value use something like this

&lt;? 
 $node=node_load($data-&gt;mybookid); // this is not precise way, you should put nid in node_load(nid);
 print $node-&gt;title;
?&gt;