Perhaps you should try some spelling variations:
demand based » demands based, demand case, demand fase
human demand » human remains, loan demand, human human
dong hoang » hong hong
based hard » based award, based hybrid
wang yang » wang yan, wang liang, wang yanling
hard coal » hard copy
coal spur » can spur
vs human » 1 human, 10 human
dong di » dong sin

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: ((((wang yang) OR (dong hoang))) OR (dong di)) vs human demand based hard coal spur ;~.
• Adding a wildcard symbol may retrieve word variants: ((((wang yang) or (dong hoang))) or (dong di)) vs human demand based hard coal spur ;*.