Perhaps you should try some spelling variations:
hanh hang » thanh hang, hang hang, hanh mang
luan hanh » luan thanh, luan han, luan danh
hanh cong » thanh cong, hang cong, hanh dong
theo hau » theo dau, theo mau, theo phap
hau sach » khau sach, cau sach, ham sach
hanh han » hanh nhan, hanh phan, hanh san
dan toan » van toan, dan than, manh toan

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo hau sach - ((hanh hang) OR (hanh han)) luan hanh cong ((dan toan) or (anh tuan)) tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo hau sach - ((hanh hang) OR (hanh han)) luan hanh cong ((dan toan) OR (anh tuan)) tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo hau sach - ((hanh hang) OR (hanh han)) luan hanh cong ((dan toan) or (anh tuan)) tap".
• Adding a wildcard symbol may retrieve word variants: theo hau sach - ((hanh hang) OR (hanh han)) luan hanh cong ((dan toan) or (anh tuan)) tap*.