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