| [1] | Foundations of cognitive grammar: Theoretical Prerequisites - Langacker - 1987 [ BOOK ] | 37 | |
| [2] | Language and Number: the emergence of a cognitive system - Hurford - 1987 [ BOOK ] | 21 | |
| [3] | The principle of contrast: A constraint on language acquisition - Clark - 1987 | 18 | |
| [4] | Emergent grammar - Hopper - 1987 | 8 |