Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
cong vang » cong lang, cong quang, cong ngang
ho chieu » theo chieu, hoc thieu, doi chieu
cong san » cong tac
toan cao » toan ban, toan tap
minh va » tinh va, sinh vat, dinh van
sinh va » sinh vat, tinh va, dinh van

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ho chieu sach - hoang ((minh va) OR (sinh va)) nhung ((cong vang) OR (cong san)) toan cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho chieu sach - hoang ((minh va) OR (sinh va)) nhung ((cong vang) or (cong san)) toan cao~".
• Adding a wildcard symbol may retrieve word variants: ho chieu sach - hoang ((minh va) OR (sinh va)) nhung ((cong vang) or (cong san)) toan cao*.