I'll post a picture of the item I found, you guys guess what book it was found in.
Here's the pic:
April 16 1940
Received from J.C. Conway
Mrs. Nils Sturbug (just a guess on that)
Edit: Here's the book:
"Sapphira and the Slave Girl" by Willa Cather. Published by Knopf, 1940.
Somehow I don't think the receipt was for the book.
-Click to enlarge photos-