Perhaps you should try some spelling variations:
trinh khau » trinh khai, trinh kham, trinh khac
trinh cao » trinh chao, trinh co, trinh cau
phan dang » phan dau, phan cong, nhan dan
nhan dang » nhan dan, tran dang
khau luat » khau luan, thau luat, phap luat
cao quan » co quan, bao quan, cao xuan
hoi viet » hai viet, thai viet, cuoi viet
cac cay » ca cay, cac cam, cac cap
van cac » van hac, van cau, van bac
oi viet » o viet, cuoi viet, gioi viet
cac mau » cam mau, sach mau
luat va » xuat va, luat ve, suat va
quan va » quan vi, quan ha, luan va
cac cau » bac cau, ca cau, cac cam
cay co » cac co, tay co, cay cong
ca cac » cua cac, va cac
co hoi » co hoc, co loi
co dan » co ban, ca dan, cao dang
co dat » coc dat, co dot, co dai
co oi » co loi, co doi, co toi
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 quan va ((cac cau) or (cac mau)) co hoi viet nam ) or ((( cong trinh khau luat va ca cac ((co dat) or (co dan)) viet nam ) or ( cong trinh ((nhan dang) OR (phan dang)) van cac cay co oi viet nam ))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( cong trinh cao quan va ((cac cau) OR (cac mau)) co hoi viet nam ) OR ((( cong trinh khau luat va ca cac ((co dat) OR (co dan)) viet nam ) OR ( cong trinh ((nhan dang) OR (phan dang)) van cac cay co oi viet nam )))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( cong trinh cao quan va ((cac cau) or (cac mau)) co hoi viet nam ) or ((( cong trinh khau luat va ca cac ((co dat) or (co dan)) viet nam ) or ( cong trinh ((nhan dang) OR (phan dang)) van cac cay co oi viet nam ))))".
• Adding a wildcard symbol may retrieve word variants: (( cong trinh cao quan va ((cac cau) or (cac mau)) co hoi viet nam ) or ((( cong trinh khau luat va ca cac ((co dat) or (co dan)) viet nam ) or ( cong trinh ((nhan dang) OR (phan dang)) van cac cay co oi viet nam ))))*.