Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
chieu sang » chieu sach, chieu xanh, hieu lang
thien van » thi van
hanh hang » thanh hang, hang hang, hanh mang
cua nhung » va nhung
hanh han » hanh nhan, hanh phan, hanh san
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 (thien van)) - ((hanh hang) OR (hanh han)) cua nhung cong tac toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sang) OR (thien van)) - ((hanh hang) OR (hanh han)) cua nhung cong tac toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu sang) or (thien van)) - ((hanh hang) OR (hanh han)) cua nhung cong tac toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sang) or (thien van)) - ((hanh hang) OR (hanh han)) cua nhung cong tac toan cao*.