Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
thu sach » tu sach, thuat sach, thuoc sach
tu cach » tu cac
va hanh » van hanh, va thanh, va danh
cao tuc » dao tuc, cao duc, cao suc
hieu va » lieu va, hieu qua
mang xa » lang xa, mang may, dang xay
ty mang » ty xang, ty hang, tin mang
va cao » va cac, va co, va dao
tuc va » thuc va, truc va, tuc xa
vi cua » vai cua, di cua
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((((tu cach) or (toc sach))) or (thu sach)) ty mang xa hoi. hieu va cao tuc va hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((tu cach) OR (toc sach))) OR (thu sach)) ty mang xa hoi. hieu va cao tuc va hanh vi cua te.
• Adding a wildcard symbol may retrieve word variants: ((((tu cach) or (toc sach))) or (thu sach)) ty mang xa hoi. hieu va cao tuc va hanh vi cua te*.