Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
lam duoc » nam duoc, luat duoc, lam thuoc
va thanh » gia thanh, ban thanh, va tinh
hieu van » thien van, lieu va, hieu ve
vai cua » dai cua, hai cua, lai cua
duoc va » nuoc va, duc va, duoc ma
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
sach ky » sach y, sach ty, sach kem
sac ky » cac ky, sai ky
x hoi » xa hoi, o hoi, x ho

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 ky) or (sac ky)) nang x hoi. ((hieu van) OR (hieu va)) lam duoc va thanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) nang x hoi. ((hieu van) OR (hieu va)) lam duoc va thanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sac ky)) nang x hoi. ((hieu van) OR (hieu va)) lam duoc va thanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sac ky)) nang x hoi. ((hieu van) OR (hieu va)) lam duoc va thanh vai cua tre*.