Perhaps you should try some spelling variations:
chieu sang » chieu xanh, hieu lang, nhieu tang
chieu sach » chinh sach, chiet tach, chieu xanh
hanh trinh » canh tranh
nhung cong » dung cong, thong cong, hang cong
cua nhung » va nhung
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
toan cao » toan ban, toan tap

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

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