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
cong soi » cong so, cong goi, cong noi
soi viet » so viet, hoi viet, oi viet
cao cay » cao cap, cho cay, tao cay
luan va » luan van, luat va
va cao » va cac, va co, va dao
lan va » lanh va, lan van, lang va
cac ty » cac ky, cac tu
co soi » cot soi, co so, co hoi

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