Perhaps you should try some spelling variations:
nhung huong » nhung phuong, nhung tuong, nhung cong
hieu quang » thieu quang, hieu quan, hieu qua
trinh quan » tinh quang, trinh luat, trinh han
trinh cua » tinh cua, trinh luat, trinh luan
hoc hieu » hoc thieu, hoc hien, doc hieu
chan ban » can ban, chan nan, chan doan
chat ban » nhat ban, chat ran, cua 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 quang - hanh ((trinh cua) or (trinh quan)) nhung huong dan ((chan ban) OR (chat ban))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu quang - hanh ((trinh cua) OR (trinh quan)) nhung huong dan ((chan ban) OR (chat ban)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hieu quang - hanh ((trinh cua) or (trinh quan)) nhung huong dan ((chan ban) OR (chat ban))".
• Adding a wildcard symbol may retrieve word variants: hoc hieu quang - hanh ((trinh cua) or (trinh quan)) nhung huong dan ((chan ban) OR (chat ban))*.