Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
dang hai » dang khai, hang hai, dung hai
thuoc ma » hoc ma, duoc ma
tu sach » thu sach, te sach, tu cach
hai cua » thai cua, dai cua, hoi cua
ma dang » da dang, ga dang, ha dang
cua tre » cua te, cuu tre, cua triet
nang ma » tang ma, sang ma, nang cao
su sach » so sach, vu sach
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (su sach)) ky nang ma hoi. ((lien quan) or (hieu qua)) nam thuoc ma dang hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang ma hoi. ((lien quan) OR (hieu qua)) nam thuoc ma dang hai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky nang ma hoi. ((lien quan) or (hieu qua)) nam thuoc ma dang hai cua tre*.