Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
hieu manh » chieu xanh, hieu nganh, dieu hanh
dung cong » dung trong
tong cong » trong cong, cong cong, dang cong
anh tang » anh bang, anh dang, anh nang
tang va » trang va, tang van, thang va
tan van » tran van, tang van, luan van

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 manh) or (chieu sach)) - anh tang va ((dung cong) or (tong cong)) tan van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((hieu manh) OR (chieu sach)) - anh tang va ((dung cong) OR (tong cong)) tan van ban.
• Adding a wildcard symbol may retrieve word variants: theo ((hieu manh) or (chieu sach)) - anh tang va ((dung cong) or (tong cong)) tan van ban*.