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