Perhaps you should try some spelling variations:
sach tham » sach nha
hanh tai » thanh tai, hang tai, han tai
sach thu » sach thue, sach thieu, cach thuc
tai cua » thai cua, tai cuc, tri cua
va hanh » van hanh, va thanh, va danh
cac duc » cac du, cao duc, cac dac
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
nang xa » lang xa, nang ma, mang xa

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 thu) or (sach tham)) ((nang xa) OR (nang x)) hoi. hieu va cac duc va hanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach thu) OR (sach tham)) ((nang xa) OR (nang x)) hoi. hieu va cac duc va hanh tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((sach thu) or (sach tham)) ((nang xa) OR (nang x)) hoi. hieu va cac duc va hanh tai cua tre".
• Adding a wildcard symbol may retrieve word variants: toc ((sach thu) or (sach tham)) ((nang xa) OR (nang x)) hoi. hieu va cac duc va hanh tai cua tre*.