System.Data.SqlClient.SqlException: Invalid column name 'Reference_Id'

I have two classes:

public class Product
{
   public Guid Id {get;set;}
   public IList<Reference> References {get;set;}
} 

public class Reference
{
   public Guid Id {get;set;}
}

Both table has many to many relationship and I added in context file.

modelBuilder.Entity<Product>()
                    .HasMany<Reference>(p => p.References)
                    .WithMany()
                    .Map(pxar =>
                    {
                        pxar.MapLeftKey("Product_Id");
                        pxar.MapRightKey("Reference_Id");
                        pxar.ToTable("ProductsXReferences");
                    });

Not sure how to fix the problem. I checked my database tables and connectionstring in Web.Config, everything looks right.