Perhaps you should try some spelling variations:
trinh cay » trinh cau, trinh may, trinh bay
trinh hoa » trinh do, trinh han
trinh cac » trinh cau, trinh chat, trinh chao
cong goi » cong noi, cong soi, dong goi
cay cong » cac cong, cao cong, cau cong
hoa tang » hoa trang, ha tang, hoa lang
hoi viet » hai viet, thai viet, cuoi viet
goi viet » gioi viet, doi viet, gai viet
cao lan » cao dang, cao tang, cao bang
van cac » van hac, van bac, dan cac
van cau » van dau, van hau, van chat
oi viet » o viet, cuoi viet, gioi viet
cac cay » ca cay, cac cam, cac cap
cao van » cac van, dao van, cao dang
co hoi » co hoc, co loi
cay co » cac co, tay co
co oi » co loi, co doi, co toi

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 lan) OR (cao van)) va cac cay co hoi viet nam ) or ( cong ((trinh cay) or (trinh cac)) lanh ((van cac) or (van cau)) cay co oi viet nam ))) or ( cong trinh hoa tang ((van cac) or (van cau)) cay cong goi viet nam ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((( cong trinh ((cao lan) OR (cao van)) va cac cay co hoi viet nam ) OR ( cong ((trinh cay) OR (trinh cac)) lanh ((van cac) OR (van cau)) cay co oi viet nam ))) OR ( cong trinh hoa tang ((van cac) OR (van cau)) cay cong goi viet nam )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((( cong trinh ((cao lan) OR (cao van)) va cac cay co hoi viet nam ) or ( cong ((trinh cay) or (trinh cac)) lanh ((van cac) or (van cau)) cay co oi viet nam ))) or ( cong trinh hoa tang ((van cac) or (van cau)) cay cong goi viet nam ))".
• Adding a wildcard symbol may retrieve word variants: (((( cong trinh ((cao lan) OR (cao van)) va cac cay co hoi viet nam ) or ( cong ((trinh cay) or (trinh cac)) lanh ((van cac) or (van cau)) cay co oi viet nam ))) or ( cong trinh hoa tang ((van cac) or (van cau)) cay cong goi viet nam ))*.