Perhaps you should try some spelling variations:
trinh chao » trinh chat, trinh han, trinh giao
trinh co » trinh do, trinh cong, trinh hoa
cay cong » cac cong, cao cong, cau cong
soi viet » so viet, hoi viet, doi viet
chao lan » cao lan, chao van, chao yang
dao cay » dao tay, dau cay, tao cay
oi viet » hoi viet, o viet, cuoi viet
va dao » ca dao
lan va » luan va, lanh va, lan van
cac ty » cac ky, cac tu

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 ban va dao cay cong ((soi viet) OR (oi viet)) nam ) or ( cong trinh chao lan va cac ty co ((soi viet) OR (oi viet)) nam ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( cong trinh co ban va dao cay cong ((soi viet) OR (oi viet)) nam ) OR ( cong trinh chao lan va cac ty co ((soi viet) OR (oi viet)) nam ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( cong trinh co ban va dao cay cong ((soi viet) OR (oi viet)) nam ) or ( cong trinh chao lan va cac ty co ((soi viet) OR (oi viet)) nam ))*".