Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
hieu van » hieu va, thien van, lieu va
van pham » san pham, van phan, van phat
so sanh » do sanh
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
vai cua » dai cua, hai cua, lai cua
cua te » cua tu
x hoi » xa hoi, o hoi, x ho

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 (so sanh)) ky nang x hoi. hieu van pham duc ((va hanh) OR (va danh)) vai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc sach) OR (so sanh)) ky nang x hoi. hieu van pham duc ((va hanh) OR (va danh)) vai cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc sach) or (so sanh)) ky nang x hoi. hieu van pham duc ((va hanh) OR (va danh)) vai cua te*".