Perhaps you should try some spelling variations:
trinh khau » trinh khai, trinh kham, trinh khac
trinh nhan » trinh han, trinh phan, trinh nha
trinh cao » trinh chao, trinh co, trinh cau
nhan dang » nhan dan, phan dang, tran dang
khau luat » khau luan, thau luat, phap luat
dang van » hoang van, hang va
cao luan » cao lan, cao quan, cao xuan
hoi viet » oi viet, thai viet, cuoi viet
hai viet » thai viet, mai viet, tai viet
cac cau » cac mau, bac cau, ca cau
luat va » xuat va, luat ve, suat va
cac tay » cac cay, cac tac, cac tai
van cac » van hac, van cau, van bac
luan va » luan van
co hoi » co hoc, co loi
tay co » ty co, cay co, tay o
ca cac » cua cac, va cac
co hai » co dai, o hai, so hai
co dan » co ban, ca dan, cao dang
co dat » coc dat, co dot, co dai
va ca » va cac, va cao, va cai

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) or (cam mau)) co hai viet nam ) or ((( cong trinh khau luat va ca cac ((co dat) or (co dan)) viet nam ) or ( cong trinh nhan dang van cac tay co hoi viet nam ))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( cong trinh cao luan va ((cac cau) OR (cam mau)) co hai viet nam ) OR ((( cong trinh khau luat va ca cac ((co dat) OR (co dan)) viet nam ) OR ( cong trinh nhan dang van cac tay co hoi viet nam )))).
• Adding a wildcard symbol may retrieve word variants: (( cong trinh cao luan va ((cac cau) or (cam mau)) co hai viet nam ) or ((( cong trinh khau luat va ca cac ((co dat) or (co dan)) viet nam ) or ( cong trinh nhan dang van cac tay co hoi viet nam ))))*.