Perhaps you should try some spelling variations:
phong chong » thong thong
nhanh lang » nhanh quang, nhanh thang, nhan dang
thong cong » tong cong, thong thong, cong cong
hieu quan » hieu qua, lieu quan, thien quan
doan van » doan va, hoang van, luan van
ho hieu » ho chieu, hoi hieu, nho hieu
lang va » lang van, hang va, lang ha

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho hieu quan - nhanh lang va ((((thong cong) OR (phong chong))) or (trong cong)) doan van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho hieu quan - nhanh lang va ((((thong cong) OR (phong chong))) OR (trong cong)) doan van ban*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho hieu quan - nhanh lang va ((((thong cong) OR (phong chong))) or (trong cong)) doan van ban*".