Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
cham doc » cham soc, chat doc, chau doc
hanh dai » hanh tai, hanh dao, vanh dai
ty nang » ty xang, ty hang, ly nang
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
doc va » duoc va, hoc va, duc va

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)) ((ty nang) OR (ky nang)) xa hoi. hieu van cham doc va hanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ((ty nang) OR (ky nang)) xa hoi. hieu van cham doc va hanh dai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ((ty nang) OR (ky nang)) xa hoi. hieu van cham doc va hanh dai cua tre*".