Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
hieu van » hieu va, thien van, lieu va
lam duoc » nam duoc, luat duoc, lam thuoc
tu sach » thu sach, su sach, te sach
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
van lam » van nam
duoc va » nuoc va, duc va, duoc ma
va dinh » van dinh, va kinh, va tinh
ket cua » ket qua, det cua, keo cua
cua tre » cua te, cuu tre, cua triet

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 (thuoc sach)) ky tang xa hoi. hieu van lam duoc va dinh ket cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thuoc sach)) ky tang xa hoi. hieu van lam duoc va dinh ket cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thuoc sach)) ky tang xa hoi. hieu van lam duoc va dinh ket cua tre*.