Perhaps you should try some spelling variations:
trung xuong » trung uong, trung duong, truong huong
theo chieu » theo tieu, ho chieu, theo chu
chieu sach » chinh sach, chiet tach, chieu sang
huong cua » dung cua
manh toan » thanh toan, anh tuan, tinh toan
long cua » luong cua, cong cua, dong cua
dan toan » van toan, dan than, xuan toan

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo chieu sach - nhanh ((long cua) or (huong cua)) trung xuong ((dan toan) OR (manh toan)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo chieu sach - nhanh ((long cua) OR (huong cua)) trung xuong ((dan toan) OR (manh toan)) cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo chieu sach - nhanh ((long cua) or (huong cua)) trung xuong ((dan toan) OR (manh toan)) cao".
• Adding a wildcard symbol may retrieve word variants: theo chieu sach - nhanh ((long cua) or (huong cua)) trung xuong ((dan toan) OR (manh toan)) cao*.