Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
chieu sach » chinh sach, chiet tach, chieu sang
theo sach » thuoc sach, te sach, theo lich
chinh cua » chinh ca, chinh sua, hinh cua
cua nhung » va nhung
tac toan » tap toan, hach toan, tich toan
tam toan » tap toan, tam than, pham toan

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc ((theo sach) or (chieu sach)) - hanh chinh cua nhung cong ((tac toan) OR (tam toan)) ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((theo sach) OR (chieu sach)) - hanh chinh cua nhung cong ((tac toan) OR (tam toan)) ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((theo sach) or (chieu sach)) - hanh chinh cua nhung cong ((tac toan) OR (tam toan)) ban".
• Adding a wildcard symbol may retrieve word variants: toc ((theo sach) or (chieu sach)) - hanh chinh cua nhung cong ((tac toan) OR (tam toan)) ban*.