Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu luc » hieu luat, hieu qua
danh dai » danh dau, danh di, danh sai
trung va » truong va, trang va, trung ha
hieu cao » chieu cao, hieu cac, hieu ca
sach ky » sac ky, sach y, sach ty
truc va » thuc va, thuc vat
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
dai cuu » dai cua, dai huu
cuu tre » cua tre, cau tren, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky lang xa hoi. ((hieu cao) or (hieu luc)) chat ((truc va) or (trung va)) danh dai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky lang xa hoi. ((hieu cao) OR (hieu luc)) chat ((truc va) OR (trung va)) danh dai cuu tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ky lang xa hoi. ((hieu cao) or (hieu luc)) chat ((truc va) or (trung va)) danh dai cuu tre*.