Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
toc sach » hoc sach, doc sach, thuoc sach
nang mai » nang ma, nang tai, nang cai
va thanh » gia thanh, ban thanh, va tinh
lang mai » lang dai, lang hai, lang man
cac dac » cac dan, cac dai, cac bac
hieu va » lieu va, hieu qua
hieu ve » hieu van
sach ly » sach y, sach lo, sach ty
cua tre » cua te, cuu tre, cua triet
dac va » duc va, day va, dat va

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ly ((nang mai) OR (lang mai)) hoi. ((hieu ve) or (hieu va)) cac dac va thanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ly ((nang mai) OR (lang mai)) hoi. ((hieu ve) OR (hieu va)) cac dac va thanh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ly ((nang mai) OR (lang mai)) hoi. ((hieu ve) or (hieu va)) cac dac va thanh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ly ((nang mai) OR (lang mai)) hoi. ((hieu ve) or (hieu va)) cac dac va thanh dai cua tre*.