Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
van hanh » van thanh, van anh, van ban
ban hanh » ban hang
tai cua » thai cua, tai cuc, tri cua
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
nam tuc » nam thuc, nam truc, nam tu
va nam » van nam, ha nam, va nay
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: ((hoc sach) or (dac sac)) ky lang xa hoi. hieu va nam tuc ((van hanh) or (ban hanh)) tai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc sach) OR (dac sac)) ky lang xa hoi. hieu va nam tuc ((van hanh) OR (ban hanh)) tai cua te.
• Adding a wildcard symbol may retrieve word variants: ((hoc sach) or (dac sac)) ky lang xa hoi. hieu va nam tuc ((van hanh) or (ban hanh)) tai cua te*.