Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
thuoc gia » thuoc giao, quoc gia, thuoc ma
thanh lay » thanh lap, thanh tay, thanh lam
dua tren » dung tren
cua viet » ca viet, hoa viet, cua vat
bach ky » bac ky
hieu he » hieu ve, hiem he, hieu le
cua tre » cua te, cuu tre, cua triet
nang o » nang co, nang ho, nang ro
he nam » ha nam, nghe nam
o hoi » co hoi, o hoc, o hai

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

• If you are trying to use Boolean operators, they must be ALL CAPS: vu bach ky nang o hoi. hieu he nam thuoc gia thanh lay ((((cua tre) OR (dua tren))) OR (cua viet))~.
• Adding a wildcard symbol may retrieve word variants: vu bach ky nang o hoi. hieu he nam thuoc gia thanh lay ((((cua tre) or (dua tren))) or (cua viet))*.