user
Instruction
Answer the question based on the provided table.


Table
Table Title: career statistics
Table Content:
<table border="1" cellspacing="0">
<tr> <td rowspan="2"> club </td> <td rowspan="2"> season </td> <td colspan="3"> league </td> <td colspan="2"> national cup </td> <td colspan="2"> league cup </td> </tr>
<tr> <td> division </td> <td> apps </td> <td> goals </td> <td> apps </td> <td> goals </td> <td> apps </td> <td> goals </td> </tr>
<tr> <td>  </td> <td> 1973 </td> <td> north american soccer league </td> <td> 19 </td> <td> 3 </td> <td colspan="2"> - </td> <td> 19 </td> <td> 3 </td> </tr>
<tr> <td> brentford </td> <td> 1974-75 </td> <td> fourth division </td> <td> 3 </td> <td> 0 </td> <td colspan="2"> - </td> <td> 3 </td> <td> 0 </td> </tr>
<tr> <td> sacramento gold </td> <td> 1979 </td> <td> american soccer league </td> <td> 26 </td> <td> 14 </td> <td colspan="2"> - </td> <td> 26 </td> <td> 14 </td> </tr>
<tr> <td> california surf </td> <td> 1981 </td> <td> north american soccer league </td> <td> 1 </td> <td> 0 </td> <td colspan="2"> - </td> <td> 1 </td> <td> 0 </td> </tr>
<tr> <td colspan="3"> career total </td> <td> 49 </td> <td> 17 </td> <td colspan="2"> - </td> <td> 49 </td> <td> 17 </td> </tr>
</table>


Question
which club did filby play for in 1981?


Answer Format
The final answer should be concise and use the following format:
```json
{
    "answer": [
        "answer1",
        "answer2",
        ...
    ]
}
```
rule
["california surf"]