Perhaps you should try some spelling variations:
chieu sang » chieu sach, chieu xanh, hieu lang
hanh sinh » hanh tinh, hanh dinh, hinh sinh
va trong » va truong, va thong, va tuong
cong bai » cuong bai, cong hai, cung bai
bai toan » bai tap
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: hoc ((dieu hanh) or (chieu sang)) - hanh sinh va trong cong bai toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((dieu hanh) OR (chieu sang)) - hanh sinh va trong cong bai toan ban.
• Adding a wildcard symbol may retrieve word variants: hoc ((dieu hanh) or (chieu sang)) - hanh sinh va trong cong bai toan ban*.