| filt | |
| industr. | pressed felt; wool felt |
| industr. construct. | fine felt; felt |
| filter | |
| el. | frequency filter; a.c.filter |
| environ. | dust arrester; dust filter; screen; strainer |
|
oversampling : 3 phrases in 2 subjects |
| Information technology | 2 |
| Municipal planning | 1 |