Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
sach kem » hanh kem
va thanh » gia thanh, ban thanh, va tinh
nam duoc » nam thuoc, da duoc, dat duoc
hieu van » hieu va, thien van, lieu va
vai cua » dai cua, hai cua, lai cua
duoc va » nuoc va, duc va, duoc ma
cua tre » cua te, cuu tre, cua triet
sach ky » sach y, sach ty, sach hay
nang o » nang co, nang ho, nang ro
sac ky » cac ky, sai ky
o hoi » co hoi, o hoc, o hai

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 (sach kem))) or (sac ky)) nang o hoi. hieu van nam duoc va thanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((((sach ky) OR (sach kem))) OR (sac ky)) nang o hoi. hieu van nam duoc va thanh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu ((((sach ky) or (sach kem))) or (sac ky)) nang o hoi. hieu van nam duoc va thanh vai cua tre*.