Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
dinh lai » dinh lam, dinh lap, dinh tai
ty hang » ly hang, thi hang, thu hang
van cam » van nam, van lam, van cau
cam duc » cam xuc, cao duc, pham duc
va dinh » van dinh, va kinh, va tinh
lai cua » dai cua, hai cua, lai chau
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: toc sach ((ty xang) or (ty hang)) xa hoi. hieu van cam duc va dinh lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ty xang) OR (ty hang)) xa hoi. hieu van cam duc va dinh lai cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ((ty xang) or (ty hang)) xa hoi. hieu van cam duc va dinh lai cua tre*.