Perhaps you should try some spelling variations:
thieu quang » thien quan, trien quang, hieu quan
nhung huong » nhung phuong, nhung tuong, nhung cong
hieu quang » hieu quan, hieu qua, diep quang
trinh quan » tinh quang, trinh luat, trinh han
trinh cua » tinh cua, trinh luat, trinh luan
gian ban » gian bana, gian dan, gian lan

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 quang) OR (thieu quang)) - hanh ((trinh cua) or (trinh quan)) nhung huong dan gian ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu quang) OR (thieu quang)) - hanh ((trinh cua) OR (trinh quan)) nhung huong dan gian ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu quang) OR (thieu quang)) - hanh ((trinh cua) or (trinh quan)) nhung huong dan gian ban".
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu quang) OR (thieu quang)) - hanh ((trinh cua) or (trinh quan)) nhung huong dan gian ban*.