Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
hanh dai » hanh tai, hanh dao, vanh dai
van hanh » van thanh, ban hanh, van anh
tuc van » thuc van, truc van, tuc va
cuu tre » cau tren, cau treo
hieu va » lieu va, hieu qua
cac tuc » cac toc, cac tu, cac tac
sach ty » sach y, sach tu, xach tay
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cua triet, dua tren

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach ty) or (sach thu)) nang xa hoi. hieu va cac tuc van hanh dai ((cuu tre) OR (cua tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ty) OR (sach thu)) nang xa hoi. hieu va cac tuc van hanh dai ((cuu tre) OR (cua tre))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ty) or (sach thu)) nang xa hoi. hieu va cac tuc van hanh dai ((cuu tre) OR (cua tre))*".