Perhaps you should try some spelling variations:
thong thuong » thong thong, hang thuong, cong thuong
trinh quan » tinh quang, trinh luat, trinh han
thuong tap » thuong gap, thuong thay, thuong mai
hoc thieu » toc thieu, hoc hien
trinh cua » tinh cua, trinh luat, trinh luan
ho chieu » theo chieu, doi chieu, mot chieu
tap toan » tap doan, tap quan, bai toan
toan cau » 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: ((ho chieu) or (hoc thieu)) tinh - hanh ((trinh cua) OR (trinh quan)) thong thuong tap toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (hoc thieu)) tinh - hanh ((trinh cua) OR (trinh quan)) thong thuong tap toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) or (hoc thieu)) tinh - hanh ((trinh cua) OR (trinh quan)) thong thuong tap toan cau".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) or (hoc thieu)) tinh - hanh ((trinh cua) OR (trinh quan)) thong thuong tap toan cau*.