Perhaps you should try some spelling variations:
trinh khau » trinh khai, trinh kham, trinh khac
trinh nhan » trinh han, trinh phan, trinh nha
khau luan » khoa luan, phap luan, pham luan
mai viet » thi viet
nhan dan » phan dau, gian dan, nhan tai
doc viet » duoc viet, hoc viet, toc viet
hai viet » thai viet, tai viet, dai viet
cao luan » cao quan, cao xuan, dao luan
cao lan » cao dang, cao tang, cao bang
cac cay » ca cay, cac cam, cac cap
van cac » van hac, van cau, van bac
dan van » dang van, doan van, dao van
cua cay » cua cac
luan va » luan van, luat va
cao van » cac van, dao van, cao dang
cac cac » cac cach, ca cac, cac bac
oi viet » hoi viet, o viet, cuoi viet
va cua » va chua, via cua, ca cua
cay co » tay co, cay cong
co doc » co duoc, co hoc, co dot
cac co » cac cong
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) OR (cao van)))) 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 dan 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) OR (cao van)))) 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 dan 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) OR (cao van)))) 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 dan van cac cay co oi viet nam ))))".
• Adding a wildcard symbol may retrieve word variants: (( cong trinh ((cao luan) or (((cao lan) OR (cao van)))) 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 dan van cac cay co oi viet nam ))))*.