Perhaps you should try some spelling variations:
phuong hang » phuong hoang, phuong bang, phuong hanh
chieu xanh » chieu sach, chieu sang, chieu tinh
tranh cua » doanh cua
ho chieu » theo chieu, hoc thieu, doi chieu
manh cua » doanh cua, ban cua
bai toan » bai tap
va toan » van toan, tap toan, va thanh

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 xanh - canh ((tranh cua) OR (manh cua)) phuong hang ((va toan) or (bai toan)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho chieu xanh - canh ((tranh cua) OR (manh cua)) phuong hang ((va toan) OR (bai toan)) cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho chieu xanh - canh ((tranh cua) OR (manh cua)) phuong hang ((va toan) or (bai toan)) cao".
• Adding a wildcard symbol may retrieve word variants: ho chieu xanh - canh ((tranh cua) OR (manh cua)) phuong hang ((va toan) or (bai toan)) cao*.