Perhaps you should try some spelling variations:
trinh chao » trinh chat, trinh co, trinh giao
trinh han » trinh quan
chao dang » cao dang, chan dang, chao yang
cau cong » cac cong, cuu cong, cao cong
han lanh » han danh, hat lanh, thanh lanh
doi viet » dai viet, hoi viet, oi viet
cay lanh » cao lan, cay lam, cay dan
lanh tao » lanh dao, lanh tho, sang tao
cong so » cong san, cong hoa
so viet » hoc viet
bac cau » bach cau, ba cau, bac can
dang va » dang van, dang vat, hang va
tao cac » tao bac, tao cao, tai cac
co lanh » co anh, co hanh, co thanh
cay co » tay co, cay cong
va bac » van bac, va cac, va bai
cac co » cac 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 ((co lanh) or (cay lanh)) tao cac ((cay co) or (cac co)) doi viet nam ) or ( cong trinh han lanh tao cac ((cay co) or (cac co)) so viet nam ))) or ( chuong trinh chao dang va bac cau cong so viet nam ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((( cong trinh ((co lanh) OR (cay lanh)) tao cac ((cay co) OR (cac co)) doi viet nam ) OR ( cong trinh han lanh tao cac ((cay co) OR (cac co)) so viet nam ))) OR ( chuong trinh chao dang va bac cau cong so viet nam )).
• Adding a wildcard symbol may retrieve word variants: (((( cong trinh ((co lanh) or (cay lanh)) tao cac ((cay co) or (cac co)) doi viet nam ) or ( cong trinh han lanh tao cac ((cay co) or (cac co)) so viet nam ))) or ( chuong trinh chao dang va bac cau cong so viet nam ))*.