Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
hieu van » thien van, lieu va, hieu ve
ban hanh » ban hang
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
xuc ban » duc ban, cuc ban, quoc ban
cua tre » cua te, cuu tre, cua triet
y lang » o lang, _ lang, tay lang
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: ((toc sach) OR (hoc sach)) y lang xa hoi. ((hieu van) or (hieu va)) cam xuc ban hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) y lang xa hoi. ((hieu van) OR (hieu va)) cam xuc ban hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (hoc sach)) y lang xa hoi. ((hieu van) or (hieu va)) cam xuc ban hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (hoc sach)) y lang xa hoi. ((hieu van) or (hieu va)) cam xuc ban hanh vi cua tre*.