Perhaps you should try some spelling variations:
dong thuong » cong thuong, dong thong, dung thuong
trinh quan » tinh quang, trinh han
thuong dan » huong dan, thuong han, thuong dam
hieu manh » chieu xanh, hieu nganh, dieu hanh
tien manh » tien anh, tien thanh, tieng anh
dan toan » van toan, dan than, manh toan
toan tap » toan ban

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 (tien manh)) - hanh ((trinh quan) OR (trinh luat)) dong thuong dan toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu manh) OR (tien manh)) - hanh ((trinh quan) OR (trinh luat)) dong thuong dan toan tap*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu manh) or (tien manh)) - hanh ((trinh quan) OR (trinh luat)) dong thuong dan toan tap*".