Perhaps you should try some spelling variations:
trinh chao » trinh chat, trinh han, trinh co
trinh nhan » trinh han, trinh phan, trinh nha
trinh cao » trinh co, trinh cau, tinh cao
nhan dang » nhan dan, phan dang, tran dang
thai viet » thi viet, tai viet, mai viet
chao luan » khao luan, phap luan, khau luan
cay cong » cac cong, cao cong, cau cong
hai viet » mai viet, tai viet, dai viet
doi viet » dai viet, hoi viet, do viet
cao luan » cao lan, cao quan, cao xuan
dang va » dang van, dang vat, hang va
oi viet » hoi viet, o viet, cuoi viet
cac cau » cac mau, bac cau, ca cau
luan va » luan van, luat va
cay co » cac co, tay co
cau co » cau do, cac co, dau co
va ca » va cao, va cai, va cau

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) OR (thai viet)) nam ) or ((( cong trinh chao luan va ca ((cay co) or (cay cong)) doi viet nam ) or ( cong trinh nhan dang va cac ((cay co) or (cay cong)) 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) OR (thai viet)) nam ) OR ((( cong trinh chao luan va ca ((cay co) OR (cay cong)) doi viet nam ) OR ( cong trinh nhan dang va cac ((cay co) OR (cay cong)) 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) OR (thai viet)) nam ) or ((( cong trinh chao luan va ca ((cay co) or (cay cong)) doi viet nam ) or ( cong trinh nhan dang va cac ((cay co) or (cay cong)) oi viet nam ))))".
• Adding a wildcard symbol may retrieve word variants: (( cong trinh cao luan va cac cau co ((hai viet) OR (thai viet)) nam ) or ((( cong trinh chao luan va ca ((cay co) or (cay cong)) doi viet nam ) or ( cong trinh nhan dang va cac ((cay co) or (cay cong)) oi viet nam ))))*.