Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
cau treo » cau theo, cau tren, cau triet
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
sach ty » sach y, sach tu, sach thu
cac tuc » cac toc, cac tu, cac tac
va hanh » van hanh, va thanh, va danh
cuu tre » cua tre, cau tren
hieu va » lieu va, hieu qua
tuc va » thuc va, truc va, tuc xa

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ty ((nang xa) or (lang xa)) hoi. hieu va cac tuc va hanh vi ((cuu tre) OR (cau treo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ty ((nang xa) OR (lang xa)) hoi. hieu va cac tuc va hanh vi ((cuu tre) OR (cau treo)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ty ((nang xa) or (lang xa)) hoi. hieu va cac tuc va hanh vi ((cuu tre) OR (cau treo))".
• Adding a wildcard symbol may retrieve word variants: hoc sach ty ((nang xa) or (lang xa)) hoi. hieu va cac tuc va hanh vi ((cuu tre) OR (cau treo))*.