Perhaps you should try some spelling variations:
thanh trung » thanh tung
luong quan » thong quan, duong qua
hieu sang » chieu sang, hieu lang, hieu quang
dap thong » phap thong, khap thong, va thong
pho thong » he thong
quan toan » quang toan, quan doan, xuan toan
doc hieu » toc thieu, hoc thieu, hoc hien
toan cao » toan ban, toan tap

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 ((dap thong) or (pho thong)) luong quan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sang - thanh trung ((dap thong) OR (pho thong)) luong quan toan cao.
• Adding a wildcard symbol may retrieve word variants: doc hieu sang - thanh trung ((dap thong) or (pho thong)) luong quan toan cao*.