Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
nhung cong » dung cong, thong cong, hang cong
hach toan » thanh toan, manh toan
ho chieu » theo chieu, hoc thieu, doi chieu
csinh va » chinh va, sinh vat, tinh va
tac toan » tap toan, tam toan, tich toan
sinh va » sinh vat, tinh va, dinh van

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

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