You can never tell what you're going to find.
You never know where you might end up when you open the pages of a book:
I generally will pick up a copy of any pigskin related Ronald Press book due to the fact that they just FEEL so damn substantial. These books have thick paper and strong spines... As it were, I received a 2nd Edition copy of Ronald Press' Football Techniques illustrated in the mail the other day and what I found inside was a neatly folded copy of the original shipping slip from 1968: