Perhaps you should try some spelling variations:
thien van » thi van
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, lieu va, hieu ve
nang xa » nang x, lang xa, nang ma
chao tu » chao xu, cho tu, cao tu
va dinh » van dinh, va tinh, vu dinh
va kinh » va tinh, qua kinh
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach y nang xa hoi. ((hieu van) or (thien van)) chao tu ((va dinh) OR (va kinh)) dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y nang xa hoi. ((hieu van) OR (thien van)) chao tu ((va dinh) OR (va kinh)) dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach y nang xa hoi. ((hieu van) or (thien van)) chao tu ((va dinh) OR (va kinh)) dai cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach y nang xa hoi. ((hieu van) or (thien van)) chao tu ((va dinh) OR (va kinh)) dai cua tre*.