Perhaps you should try some spelling variations:
thanh toan » thanh hoa, thanh san, tinh toan
hanh trong » hanh trang, anh trong, hinh trong
doi chieu » doc hieu, ho chieu, mot chieu
dung cong » dung trong
hinh toan » tinh toan, trinh toan, manh toan
trong ac » trong cac, trong bac, trong lac
doi chi » doi khi
ac dung » tac dung, ap dung, a dung

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: ((doi chieu) OR (doi chi)) xanh - hanh trong ac dung cong ((hinh toan) OR (thanh toan)) cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doi chieu) OR (doi chi)) xanh - hanh trong ac dung cong ((hinh toan) or (thanh toan)) cau~".
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) OR (doi chi)) xanh - hanh trong ac dung cong ((hinh toan) or (thanh toan)) cau*.