Perhaps you should try some spelling variations:
hanh dai » hanh tai, hanh dao, vanh dai
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
lang ha » long ha
lang xa » dang xay, lang van
cua tre » cua te, cuu tre, cua triet
van am » van nam, van lam, van dam

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

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