Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
cong thanh » dong thanh, cong trinh, cong tan
thanh toan » thanh hoa, thanh san, tinh toan
trung hoc » trung quoc
hang cong » dang cong, hang nong, bang cong
hieu van » hieu va, thien van, lieu va
trung ha » trung tam, trung cap
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: ho ((hieu van) or (hieu quang)) - hanh ((trung ha) OR (trung hoc)) hang cong thanh toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu van) OR (hieu quang)) - hanh ((trung ha) OR (trung hoc)) hang cong thanh toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu van) or (hieu quang)) - hanh ((trung ha) OR (trung hoc)) hang cong thanh toan cao".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu van) or (hieu quang)) - hanh ((trung ha) OR (trung hoc)) hang cong thanh toan cao*.