Perhaps you should try some spelling variations:
nang mai » nang ma, nang tai, lang mai
va thanh » gia thanh, ban thanh, le thanh
te sach » toc sach
cac dac » cac dan, cac dai, cac bac
va tinh » may tinh
hieu va » lieu va, hieu qua
sach ly » sach y, sach lo, sach ty
hieu ve » hieu van
mai hoi » mai khoi, dai hoi, lai hoi
ly nang » ky nang, ly hang, ly vang
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 ly nang mai hoi. ((hieu ve) or (hieu va)) cac dac ((va thanh) OR (va tinh)) dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ly nang mai hoi. ((hieu ve) OR (hieu va)) cac dac ((va thanh) OR (va tinh)) dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ly nang mai hoi. ((hieu ve) or (hieu va)) cac dac ((va thanh) OR (va tinh)) dai cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ly nang mai hoi. ((hieu ve) or (hieu va)) cac dac ((va thanh) OR (va tinh)) dai cua tre*.