Perhaps you should try some spelling variations:
trinh may » trinh ky, trinh han, trinh ly
soi viet » hoi viet, oi viet, doi viet
may ban » may san, tay ban, may van
so viet » hoc viet
cac cap » cao cap, cac cam, cac cau
cau co » cau do, cac co, dau co
cay co » cac co, tay co, cay cong
cap do » cau do
do soi » do moi, do son, do sai

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 may ban va cac ((cau co) OR (cay co)) soi viet nam ) or ( cong trinh may ban va cac ((cau co) OR (cay co)) so viet nam ))) or ( cong trinh may ban va cac cap do soi viet nam ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((( cong trinh may ban va cac ((cau co) OR (cay co)) soi viet nam ) OR ( cong trinh may ban va cac ((cau co) OR (cay co)) so viet nam ))) OR ( cong trinh may ban va cac cap do soi viet nam )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((( cong trinh may ban va cac ((cau co) OR (cay co)) soi viet nam ) or ( cong trinh may ban va cac ((cau co) OR (cay co)) so viet nam ))) or ( cong trinh may ban va cac cap do soi viet nam ))".
• Adding a wildcard symbol may retrieve word variants: (((( cong trinh may ban va cac ((cau co) OR (cay co)) soi viet nam ) or ( cong trinh may ban va cac ((cau co) OR (cay co)) so viet nam ))) or ( cong trinh may ban va cac cap do soi viet nam ))*.