Perhaps you should try some spelling variations:
when coal » when goal, women coal, when can
coal ming » coal mine, coal mining, coal mines
dong bin » dong sin, dong di, dann bin
bin dann » sein dann, bin da, ein dank
yang yi » yang jui
yang xi » yang jui
dann 3 » dann _, ann 3, dann 4.3
3 when » 4 when

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: dong bin dann 3 when coal ming ((((wang yan) OR (yang yi))) OR (((yang xi) OR (yang di)))) ;~.
• Adding a wildcard symbol may retrieve word variants: dong bin dann 3 when coal ming ((((wang yan) or (yang yi))) or (((yang xi) or (yang di)))) ;*.