Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
thu lang » thu hang, thu bang, phu lang
hieu van » hieu va, thien van, lieu va
so sach » so sanh, bo sach, co sach
lang xa » lang ha, dang xay, lang van
van cam » van nam, van lam, van cau
cua tre » cua te, cuu tre, cua triet
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: so sach thu lang xa hoi. hieu van cam ((duc va) or (hoc va)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach thu lang xa hoi. hieu van cam ((duc va) OR (hoc va)) hanh vi cua tre*.