Perhaps you should try some spelling variations:
duoc tuan » duoc luan, quoc tuan, duoc thanh
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
nam duoc » nam thuoc, da duoc, dat duoc
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
anh va » hanh va
va cua » va chua, via cua, ca cua

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 y ((nang xa) or (nang ma)) hoi. hieu van nam duoc tuan anh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y ((nang xa) OR (nang ma)) hoi. hieu van nam duoc tuan anh va cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach y ((nang xa) or (nang ma)) hoi. hieu van nam duoc tuan anh va cua tre*.