Perhaps you should try some spelling variations:
dung thuong » hang thuong, cong thuong, dung thuoc
theo chieu » theo tieu, ho chieu, theo chu
canh trinh » canh tranh, hanh trinh, canh tinh
trinh qua » trinh quan, trinh cua, trinh quang
dam toan » dan toan, tam toan, dam thanh
toan cao » toan ban, toan tap

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) or (cuc thue)) sach - canh trinh qua ((dung thuong) OR (dung trong)) dam toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((theo chieu) OR (cuc thue)) sach - canh trinh qua ((dung thuong) OR (dung trong)) dam toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((theo chieu) or (cuc thue)) sach - canh trinh qua ((dung thuong) OR (dung trong)) dam toan cao".
• Adding a wildcard symbol may retrieve word variants: ((theo chieu) or (cuc thue)) sach - canh trinh qua ((dung thuong) OR (dung trong)) dam toan cao*.