Perhaps you should try some spelling variations:
hieu luat » hieu qua
manh tran » manh toan, manh tuan, canh tranh
bien soat » bien soan, kiem soat, bien so
van hieu » cao hieu
tran tri » trang tri, tran thi, trang trai
vat bien » vat lieu, cam bien
tri vat » tri va, tri van, trinh vat
lien » vien, tien, dien
luan » lan

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( lien quan luan van hieu luat ) or ( manh tran tri vat bien soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( lien quan luan van hieu luat ) OR ( manh tran tri vat bien soat )).
• Adding a wildcard symbol may retrieve word variants: (( lien quan luan van hieu luat ) or ( manh tran tri vat bien soat ))*.