Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
chieu xanh » chieu sach, chieu sang, chieu tinh
nhung cong » dung cong, thong cong, hang cong
hieu manh » hieu nganh, dieu hanh, hien hanh
trinh va » trinh van, trinh vat, trinh ve
vat phan » va phan, van phan, sat phan
phan cau » phan dau, phan cac, phan tu

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 ((nhung cong) or (trong cong)) vat phan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu manh) OR (chieu xanh)) - canh trinh va ((nhung cong) OR (trong cong)) vat phan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu manh) OR (chieu xanh)) - canh trinh va ((nhung cong) or (trong cong)) vat phan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu manh) OR (chieu xanh)) - canh trinh va ((nhung cong) or (trong cong)) vat phan cau*.