diff --git a/main.py b/main.py
index a999fba..d0b2863 100644
--- a/main.py
+++ b/main.py
@@ -52,7 +52,8 @@ class Book(db.Model):
     author = db.relationship('Author', secondary=book_author_link)
     publisher = db.relationship('Publisher', secondary=book_publisher_link)
     genre = db.relationship('Genre_Lst', secondary=book_genre_link )
-    subs = db.relationship('Book_Sub_Book_Link', secondary=Book_Sub_Book_Link.__table__, primaryjoin="Book.id==Book_Sub_Book_Link.sub_book_id", secondaryjoin="Book.id==Book_Sub_Book_Link.book_id" )
+    parent_ref = db.relationship('Book_Sub_Book_Link', secondary=Book_Sub_Book_Link.__table__, primaryjoin="Book.id==Book_Sub_Book_Link.sub_book_id", secondaryjoin="Book.id==Book_Sub_Book_Link.book_id" )
+    child_ref = db.relationship('Book_Sub_Book_Link', secondary=Book_Sub_Book_Link.__table__, primaryjoin="Book.id==Book_Sub_Book_Link.book_id", secondaryjoin="Book.id==Book_Sub_Book_Link.sub_book_id" )
 
     def __repr__(self):
         return "<id: {}, author: {}, title: {}, year_published: {}, rating: {}, condition: {}, owned: {}, covertype: {}, notes: {}, blurb: {}, created: {}, modified: {}, publisher: {}>".format(self.id, self.author, self.title, self.year_published, self.rating, self.condition, self.owned, self.covertype, self.notes, self.blurb, self.created, self.modified, self.publisher )
@@ -109,7 +110,8 @@ class BookSchema(ma.SQLAlchemyAutoSchema):
     author = ma.Nested(AuthorSchema, many=True)
     publisher = ma.Nested(PublisherSchema, many=True)
     genre = ma.Nested(Genre_LstSchema, many=True)
-    subs = ma.Nested(Book_Sub_Book_LinkSchema, many=True)
+    parent_ref = ma.Nested(Book_Sub_Book_LinkSchema, many=True)
+    child_ref = ma.Nested(Book_Sub_Book_LinkSchema, many=True)
     class Meta:
         model = Book
         include_relationships = True
@@ -157,8 +159,10 @@ def book(id):
 
     book_s['sub_book'] = sub_book
 
-    print( book.genre )
-    print( book.subs )
+    print( "parent book details:" )
+    print( book.parent_ref )
+    print( "child book details:" )
+    print( book.child_ref )
 
     return render_template("books.html", books=book_s, subs=sub_book )