Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
viet cau » viet chau, viet ca, viet chu
te sach » toc sach
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va hanh » va thanh, va danh, ban hanh
y nang » ky nang, ly nang, v nang
va dam » van dam, va dao, va dau
dam tu » nam tu, cam tu, tam tu
ve cau » ke cau, va cau, ve cac

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 y nang xa hoi. hieu va dam tu ((va hanh) OR (van hanh)) ((viet cau) or (ve cau)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y nang xa hoi. hieu va dam tu ((va hanh) OR (van hanh)) ((viet cau) OR (ve cau)) tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y nang xa hoi. hieu va dam tu ((va hanh) OR (van hanh)) ((viet cau) or (ve cau)) tren".
• Adding a wildcard symbol may retrieve word variants: te sach y nang xa hoi. hieu va dam tu ((va hanh) OR (van hanh)) ((viet cau) or (ve cau)) tren*.