Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
thanh dai » thanh hai, thanh tai, thanh dat
va thanh » gia thanh, ban thanh, va tinh
sach ty » sach y, sach tu, sach thu
tang ma » mang may, tang van
lang xa » lang ha, dang xay, lang van
cac duc » cac du, cao duc, cac nuoc
cac dac » cac dan, cac dai, cac bac
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: thuat sach ty ((tang ma) or (lang xa)) hoi. lieu va ((cac duc) OR (cac dac)) va thanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ty ((tang ma) OR (lang xa)) hoi. lieu va ((cac duc) OR (cac dac)) va thanh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach ty ((tang ma) or (lang xa)) hoi. lieu va ((cac duc) OR (cac dac)) va thanh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: thuat sach ty ((tang ma) or (lang xa)) hoi. lieu va ((cac duc) OR (cac dac)) va thanh dai cua tre*.