Perhaps you should try some spelling variations:
trinh cay » trinh cau, trinh may, trinh cac
soi viet » hoi viet, oi viet, doi viet
sai viet » san viet, mai viet, tai viet
cay ban » can ban, cac ban, tay ban
cac cay » ca cay, cac cam, cac cau
so viet » hoc viet
cac cap » cao cap, cac cam, cac cau
cay co » cac co, tay co, cay cong
co soi » cot soi, co hoi, co loi
cap do » cau do
do sai » do dai, do hai, do mai

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 cay ban va cac cay co soi viet nam ) or ( cong trinh cay ban va cac cay co so viet nam ))) or ( cong trinh cay ban va cac cap do sai viet nam ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((( cong trinh cay ban va cac cay co soi viet nam ) OR ( cong trinh cay ban va cac cay co so viet nam ))) OR ( cong trinh cay ban va cac cap do sai viet nam )).
• Adding a wildcard symbol may retrieve word variants: (((( cong trinh cay ban va cac cay co soi viet nam ) or ( cong trinh cay ban va cac cay co so viet nam ))) or ( cong trinh cay ban va cac cap do sai viet nam ))*.