| Edition 1 - 1975 |
Edition 2 - 1978 |
Edition 3 - 1979 |
Edition 4 - 1996 |
Edition 5 - 2001 |
| | Always first steps | Always the first steps | Always first steps |
| | Not building a wall but making a brick | Not building a wall; making a brick | Not building a wall but making a brick |
| | Question the heroic approach | Question the heroic | Question the heroic approach |
| | Simply a matter of work | It is simply a matter of work | Simply a matter of work |
| | State the problem in words as clearly as possible | State the problem as clearly as possible | State the problem in words as clearly as possible |
| | The most important thing is the thing most easily forgotten | The most easily forgotten thing is the most important | The most important thing is the thing most easily forgotten |
| | Towards the insignificant | Move towards the unimportant | Towards the insignificant |