Perhaps you should try some spelling variations:
thanh trung » thanh tung
thuat hung » thuat dung, thuat ung, thuat xung
tran trong » gian trong, quan trong, tran hong
hieu sang » chieu sang, hieu lang, hieu quang
doc hieu » toc thieu, hoc thieu, hoc hien
cong san » cong tac
phan lap » phan dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc hieu sang - thanh trung ((thuat hung) or (tran trong)) cong san ((phan lap) or (thanh san))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sang - thanh trung ((thuat hung) OR (tran trong)) cong san ((phan lap) OR (thanh san)).
• Adding a wildcard symbol may retrieve word variants: doc hieu sang - thanh trung ((thuat hung) or (tran trong)) cong san ((phan lap) or (thanh san))*.