Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
luat nhung » luat chung, luat thuong, thuat nhung
nhung cong » dung cong, thong cong, hang cong
hoc thieu » toc thieu, hoc hien
ho chieu » theo chieu, doi chieu, mot chieu
ban toan » ban than, van toan, bao toan
bai toan » bai tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((ho chieu) or (hoc thieu)) xanh - canh trinh luat nhung cong ((ban toan) OR (bai toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (hoc thieu)) xanh - canh trinh luat nhung cong ((ban toan) OR (bai toan)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) or (hoc thieu)) xanh - canh trinh luat nhung cong ((ban toan) OR (bai toan)) cau".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) or (hoc thieu)) xanh - canh trinh luat nhung cong ((ban toan) OR (bai toan)) cau*.