Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
tranh cua » doanh cua, manh cua
hang cong » hang nong, bang cong, thanh cong
dang cong » dung cong
manh toan » thanh toan, anh tuan, tinh toan
hoc hieu » hoc thieu, hoc hien, doc hieu
tang cua » mang cua, hang cua, tang luan
toan ban » van ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hieu quang - hanh ((tranh cua) or (tang cua)) ((hang cong) OR (dang cong)) manh toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu quang - hanh ((tranh cua) OR (tang cua)) ((hang cong) OR (dang cong)) manh toan ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hieu quang - hanh ((tranh cua) or (tang cua)) ((hang cong) OR (dang cong)) manh toan ban".
• Adding a wildcard symbol may retrieve word variants: hoc hieu quang - hanh ((tranh cua) or (tang cua)) ((hang cong) OR (dang cong)) manh toan ban*.