Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
chat doc » chat hoc, chau doc, thuat doc
chat duc » chat xuc, chet duoc, pham duc
anh dai » vanh dai, anh bai, anh dat
vu sach » vu bach, su sach, vu khach
te sach » toc sach
cua tre » cua te, cuu tre, cua triet
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sach) or (te sach)) ky nang o hoi. hieu van ((chat duc) OR (chat doc)) tuan anh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (te sach)) ky nang o hoi. hieu van ((chat duc) OR (chat doc)) tuan anh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (te sach)) ky nang o hoi. hieu van ((chat duc) OR (chat doc)) tuan anh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (te sach)) ky nang o hoi. hieu van ((chat duc) OR (chat doc)) tuan anh dai cua tre*.