| Title / Condition | Seller | Highlights | Price |
|---|---|---|---|
| On Problem-solving: 58 (Godkin Lectures at Harvard University) Karl Duncker / New - Hardcover | Kennys Bookshop and Art Galleries Ltd. | $252.74 | |
| On Problem-solving: 58 (Godkin Lectures at Harvard University) Karl Duncker / New - Hardcover | Kennys Bookstore | $204.05 |