Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
nam duoc » nam thuoc, da duoc, dat duoc
hieu van » hieu va, thien van, lieu va
lai hoi » dai hoi, lai hoa, lai roi
hanh va » hang va, hanh vi
ma hanh » va hanh, da hanh, na hanh
duoc ma » duoc lam
cua tre » cua te, cuu tre, cua triet
mai hoi » mai khoi, dai hoi, mai doi
ly nang » ky nang, ly hang, ly vang
ly van » le van, ly va, ly von
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 ((ly nang) or (ly van)) ((mai hoi) OR (lai hoi)). hieu van nam duoc ma hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ly nang) OR (ly van)) ((mai hoi) OR (lai hoi)). hieu van nam duoc ma hanh va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((ly nang) or (ly van)) ((mai hoi) OR (lai hoi)). hieu van nam duoc ma hanh va cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ((ly nang) or (ly van)) ((mai hoi) OR (lai hoi)). hieu van nam duoc ma hanh va cua tre*.