Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, nhung don
hieu quan » hieu qua, lieu quan, thien quan
trong cua » truong cua, thong cua, trong qua
hang cong » dang cong, hang nong, bang cong
tang luan » dung luan
hoc hieu » hoc thieu, hoc hien, doc hieu
trong ca » trong cac, trong nha

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 quan - anh ((trong cua) or (trong ca)) ((nhung cong) or (hang cong)) tang luan van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu quan - anh ((trong cua) OR (trong ca)) ((nhung cong) OR (hang cong)) tang luan van.
• Adding a wildcard symbol may retrieve word variants: hoc hieu quan - anh ((trong cua) or (trong ca)) ((nhung cong) or (hang cong)) tang luan van*.