P S ยท Penny Summers
| title | ISBN-13 (ISBN-10) | year of publication |
|---|---|---|
| Sommers: Instructor's Manual & Test Item File for Microeconomics Theo Etc 5ed | 978-0-393-95409-8 (0-393-95409-9) | 1986 |
| Sommers Microeconomics - Theory and Applications 4edinstructors Manual | 978-0-393-95215-5 (0-393-95215-0) | 1982 |