Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
hoc thieu » toc thieu, hoc hien
cong dan » cong tan, huong dan, cong dong
cong san » cong tac
toan cau » toan cao, toan ban, toan tap
can van » cac van, can ban, tan van
van va » van vat, van van, ban va

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thieu sach - can van va nhung ((cong dan) or (cong san)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sach - can van va nhung ((cong dan) OR (cong san)) toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc thieu sach - can van va nhung ((cong dan) or (cong san)) toan cau*.