C C · C Christensen · n/c · N. Christensen
| title | ISBN-13 | year of publication |
|---|---|---|
| Secrets of the hard sell | 978-0-13-798058-1 | 1975 |
| The art of persuasion for sales managers | 978-0-13-047829-0 | 1971 |
| The Art of Persuasion in Selling | 978-0-13-048009-5 | 1970 |
| The magic power of command selling: how to take charge of the sale | 978-0-13-545269-1 | 1973 |