Perhaps you should try some spelling variations:
thanh dat » thanh san, thanh hai, thanh van
hieu van » hieu va, thien van, lieu va
dat cua » dai cua, day cua, mat cua
te sach » toc sach
hieu ve » hieu va
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
dac va » day va, dat va, dai va
ma hoi » mai hoi, xa hoi, ma hoa

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

• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y nang ma hoi. ((hieu ve) OR (hieu van)) cac ((dac va) OR (duc va)) thanh dat cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y nang ma hoi. ((hieu ve) or (hieu van)) cac ((dac va) OR (duc va)) thanh dat cua tre~".
• Adding a wildcard symbol may retrieve word variants: te sach y nang ma hoi. ((hieu ve) or (hieu van)) cac ((dac va) OR (duc va)) thanh dat cua tre*.