Perhaps you should try some spelling variations:
trinh khau » trinh khai, trinh kham, trinh khac
trinh nhan » trinh han, trinh phan, trinh nha
nhan dang » nhan dan, phan dang, tran dang
khau luan » khoa luan, phap luan, pham luan
doc viet » duoc viet, hoc viet, toc viet
hai viet » thai viet, tai viet, dai viet
dang van » hoang van, hang va
mai viet » thi viet
cao luan » cao quan, cao xuan, dao luan
oi viet » hoi viet, o viet, cuoi viet
cac cay » ca cay, cac cam, cac cap
van cac » van hac, van cau, van bac
cao lan » cao van, cao dang, cao tang
luan va » luan van, luat va
cac cac » cac cach, ca cac, cac bac
cua cay » cua cac
co doc » co duoc, co hoc, co dot
cay co » tay co, cay cong
cac co » cac cong
va cua » va chua, via cua, ca cua
co oi » co hoi, co loi, co doi

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( cong trinh ((cao luan) OR (cao lan)) va cac cac co ((hai viet) or (mai viet)) nam ) or ((( cong trinh khau luan va cua cay co doc viet nam ) or ( cong trinh nhan dang van cac cay co oi viet nam ))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( cong trinh ((cao luan) OR (cao lan)) va cac cac co ((hai viet) OR (mai viet)) nam ) OR ((( cong trinh khau luan va cua cay co doc viet nam ) OR ( cong trinh nhan dang van cac cay co oi viet nam )))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( cong trinh ((cao luan) OR (cao lan)) va cac cac co ((hai viet) or (mai viet)) nam ) or ((( cong trinh khau luan va cua cay co doc viet nam ) or ( cong trinh nhan dang van cac cay co oi viet nam ))))".
• Adding a wildcard symbol may retrieve word variants: (( cong trinh ((cao luan) OR (cao lan)) va cac cac co ((hai viet) or (mai viet)) nam ) or ((( cong trinh khau luan va cua cay co doc viet nam ) or ( cong trinh nhan dang van cac cay co oi viet nam ))))*.