Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
doi chieu » doc hieu, doi chi, mot chieu
ho chieu » theo chieu, hoc thieu, mot chieu
csinh va » chinh va, sinh vat, tinh va
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
toan ban » van ban
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) or (doi chieu)) sach - hanh ((csinh va) or (sinh va)) nhung cong tac toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (doi chieu)) sach - hanh ((csinh va) OR (sinh va)) nhung cong tac toan ban.
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) or (doi chieu)) sach - hanh ((csinh va) or (sinh va)) nhung cong tac toan ban*.