Perhaps you should try some spelling variations:
trinh quang » tinh quang, trinh quan, trinh dung
tranh quang » tran quang, tinh quang, trinh quan
theo hieu » theo chieu, thien hieu, thuc hieu
bang cong » dang cong, bang song, hang cong
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
toan tap » toan ban

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

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