Perhaps you should try some spelling variations:
trinh nhan » trinh han, trinh phan, trinh nha
trinh khau » trinh khai, trinh kham, trinh khac
trinh cao » trinh chao, trinh co, trinh cau
nhan dang » nhan dan, phan dang, tran dang
khau luan » khoa luan, phap luan, pham luan
thai viet » thi viet, tai viet, mai viet
cao luan » cao lan, cao quan, cao xuan
hai viet » mai viet, tai viet, dai viet
hoi viet » cuoi viet, gioi viet, thi viet
cac cay » cac cam, cac cap, tac cay
dang va » dang van, dang vat, hang va
oi viet » o viet, cuoi viet, gioi viet
luan va » luan van, luat va
cac cau » cac mau, bac cau, ca cau
ca cay » cua cay, ca cac, ca cao
co hai » co dai, co hoi, o hai
cau co » cau do, cac co, dau co
cay co » cac co, tay co, cay cong
va ca » va cao, va cai, va cau
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 va cac cau co hai viet nam ) or ((( cong trinh khau luan va ca cay co ((hoi viet) OR (thai viet)) nam ) or ( cong trinh nhan dang va cac cay co oi viet nam ))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( cong trinh cao luan va cac cau co hai viet nam ) OR ((( cong trinh khau luan va ca cay co ((hoi viet) OR (thai viet)) nam ) OR ( cong trinh nhan dang va cac cay co oi viet nam )))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( cong trinh cao luan va cac cau co hai viet nam ) or ((( cong trinh khau luan va ca cay co ((hoi viet) OR (thai viet)) nam ) or ( cong trinh nhan dang va cac cay co oi viet nam ))))".
• Adding a wildcard symbol may retrieve word variants: (( cong trinh cao luan va cac cau co hai viet nam ) or ((( cong trinh khau luan va ca cay co ((hoi viet) OR (thai viet)) nam ) or ( cong trinh nhan dang va cac cay co oi viet nam ))))*.