Perhaps you should try some spelling variations:
sach tham » sach nha
thanh vai » thanh hai, thanh van, thanh tai
toc sach » hoc sach, doc sach, thuoc sach
va thanh » gia thanh, ban thanh, va tinh
vai cua » dai cua, hai cua, lai cua
cac luc » cau luc, cac nuoc, cac cuoc
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
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: toc sach tham ((nang xa) or (nang cao)) hoi. hieu va ((cac luc) OR (coc luc)) va thanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach tham ((nang xa) OR (nang cao)) hoi. hieu va ((cac luc) OR (coc luc)) va thanh vai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach tham ((nang xa) or (nang cao)) hoi. hieu va ((cac luc) OR (coc luc)) va thanh vai cua tre*".