| title | ISBN-13 (ISBN-10) | year of publication |
|---|---|---|
| Analyses of consciousness as well as observation, volition and valuation | 978-91-554-0664-6 (91-554-0664-5) | 1977 |
| What Is Concept Analysis? | 978-91-22-01479-9 (91-22-01479-9) | 1992 |
| What is intelligence?: Analyses of theories propounded by intelligence scientists of the twentieth century: moreover the results of the testings of about 3000 individuals with two new univocal tests | 978-91-22-00404-2 (91-22-00404-1) | 1980 |