Perhaps you should try some spelling variations:
trinh phuong » trinh dung, trinh cong, trinh phan
trinh huong » tinh huong, trinh dung, dinh huong
trinh duong » trinh dung, dinh duong, binh duong
hieu soat » hieu suat, hieu hoat, kiem soat
hieu luat » hieu qua
luan va » luan van, luat va

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: ((((trinh huong) OR (trinh phuong))) OR (trinh duong)) luan va ((hieu soat) OR (hieu luat))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((trinh huong) OR (trinh phuong))) or (trinh duong)) luan va ((hieu soat) or (hieu luat))~".
• Adding a wildcard symbol may retrieve word variants: ((((trinh huong) OR (trinh phuong))) or (trinh duong)) luan va ((hieu soat) or (hieu luat))*.