| W97-1511 | statistical NL applications apply | backing-off estimation | techniques to handle lowfrequency |
| E91-1004 | natural language applications employ | backing-off estimation | technique * 11 -LSB- 51 to handle |
| H91-1044 | natural langnage applications employ | backing-off estimation | techniqnes \ -LSB- 10 \ -RSB- |
