Perhaps you should try some spelling variations:
tranh luan » trinh luan, trinh luat, doanh luan
luan chung » luan chinh
hieu cach » hieu cac, chieu sach, hieu ca
hoang van » hang va
trong van » trong cac
hoc hieu » hoc thieu, hoc hien, doc hieu
tuan cau » toan cau, quan cau, tuan cu

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 cach - canh tranh luan chung ((hoang van) or (trong van)) tuan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu cach - canh tranh luan chung ((hoang van) OR (trong van)) tuan cau.
• Adding a wildcard symbol may retrieve word variants: hoc hieu cach - canh tranh luan chung ((hoang van) or (trong van)) tuan cau*.