Perhaps you should try some spelling variations:
khanh vai » khanh van, hanh vi, hanh va
dat khanh » van khanh, duy khanh
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
vai cua » dai cua, hai cua, lai cua
tuc dat » tu dat, tuc dan, tuc hat
ban tuc » ban tu, ban tum, ban thuoc
sang ma » tang ma, sang tao, mang may
nang ma » tang ma, nang cao, mang may
te sach » toc sach
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: ((thu sach) or (te sach)) va ((nang ma) or (sang ma)) hoi. hieu van ban tuc dat khanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (te sach)) va ((nang ma) OR (sang ma)) hoi. hieu van ban tuc dat khanh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (te sach)) va ((nang ma) or (sang ma)) hoi. hieu van ban tuc dat khanh vai cua tre*.