Perhaps you should try some spelling variations:
chieu xanh » chieu sach, chieu sang, chieu tinh
thong cong » trong cong, tong cong, thong thong
hieu manh » hieu nganh, dieu hanh, hien hanh
trinh va » trinh van, trinh vat, trinh vi
trinh ve » trinh he, trinh vi, trinh viet
cong san » cong tac
san phan » san pham, van phan, sat phan
phan dau » phan tu, hang dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((hieu manh) OR (chieu xanh)) - canh ((trinh va) or (trinh ve)) thong cong san phan dau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu manh) OR (chieu xanh)) - canh ((trinh va) OR (trinh ve)) thong cong san phan dau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu manh) OR (chieu xanh)) - canh ((trinh va) or (trinh ve)) thong cong san phan dau".
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu manh) OR (chieu xanh)) - canh ((trinh va) or (trinh ve)) thong cong san phan dau*.