Perhaps you should try some spelling variations:
trinh cao » trinh chao, trinh co, tinh cao
trinh cau » trinh chat, trinh chao, trinh tu
tai viet » thi viet, mai viet, tai lieu
hai viet » thai viet, mai viet, dai viet
cau giay » cuu giai, cac giai
cau luan » cu luan, dau luan, lau luan
soi viet » hoi viet, doi viet, noi viet
cao cay » cao cap, cho cay, tao cay
cao cao » cao cap, bao cao, tao cao
van cao » van dao, van bao, van hao
oi viet » hoi viet, o viet, cuoi viet
cao van » cac van, dao van, cao dang
so viet » hoc viet
cao so » cao son, cao su, cao do
van va » van vat, van van, ban va
cay co » cac co, tay co, cay cong

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 van va ((cau xay) or (cau giay)) co ((soi viet) or (oi viet)) nam ) or ((( chuong trinh cau luan van cao cao so ((hai viet) or (tai viet)) nam ) or ( chuong trinh cau luan van cao cay co so viet nam ))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( cong trinh cao van va ((cau xay) OR (cau giay)) co ((soi viet) OR (oi viet)) nam ) OR ((( chuong trinh cau luan van cao cao so ((hai viet) OR (tai viet)) nam ) OR ( chuong trinh cau luan van cao cay co so viet nam )))).
• Adding a wildcard symbol may retrieve word variants: (( cong trinh cao van va ((cau xay) or (cau giay)) co ((soi viet) or (oi viet)) nam ) or ((( chuong trinh cau luan van cao cao so ((hai viet) or (tai viet)) nam ) or ( chuong trinh cau luan van cao cay co so viet nam ))))*.