Perhaps you should try some spelling variations:
dang thanh » dong thanh, dang hanh, hoang thanh
hanh trinh » canh tranh, hanh chinh
thau khau » thau kham, nhap khau, tham khao
khau sach » hau sach, khoa sach, pham sach
dang cong » dung cong
dang tran » quang tran, hoang tran, dang van
trinh va » trinh van, trinh vat, trinh ve
va dang » van dang, va nang, va lang

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

• Performing a fuzzy search may retrieve terms with similar spellings: thau khau sach - hanh trinh va dang cong ((dang tran) or (dang thanh)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thau khau sach - hanh trinh va dang cong ((dang tran) OR (dang thanh)) cao.
• Adding a wildcard symbol may retrieve word variants: thau khau sach - hanh trinh va dang cong ((dang tran) or (dang thanh)) cao*.