Perhaps you should try some spelling variations:
trinh cau » trinh chat, trinh chao, trinh tu
trinh cao » trinh chao, trinh co, tinh cao
cao lanh » cao lan, cao anh, cao danh
toi viet » thi viet, tai viet, hoi viet
lanh van » lang van, lanh va, canh van
doi viet » dai viet, hoi viet, oi viet
cho toi » cho tuoi, cho moi, cho doi
cac cho » cap cho, cao cho, dac cho
cao cac » cho cac, cao cap, ca cac
anh van » anh va, thanh van, doanh van
dao cao » dao tao, bao cao, tao cao
cac co » cac cong
co doi » cho doi, co dot, co dai

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 cau ((lanh van) OR (anh van)) cao cac cho toi viet nam ) or ( chuong trinh cao lanh dao cao cac co doi viet nam ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( cong trinh cau ((lanh van) OR (anh van)) cao cac cho toi viet nam ) OR ( chuong trinh cao lanh dao cao cac co doi viet nam )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( cong trinh cau ((lanh van) OR (anh van)) cao cac cho toi viet nam ) or ( chuong trinh cao lanh dao cao cac co doi viet nam ))".
• Adding a wildcard symbol may retrieve word variants: (( cong trinh cau ((lanh van) OR (anh van)) cao cac cho toi viet nam ) or ( chuong trinh cao lanh dao cao cac co doi viet nam ))*.