Perhaps you should try some spelling variations:
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va danh » va dan, va hanh, dia danh
va dinh » van dinh, va kinh, va tinh
cua tre » cua te, cuu tre, cua triet
va dam » van dam, va dao, va dau
dam tu » nam tu, cam tu, tam tu
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (do sanh)) ky nang xa hoi. hieu va dam tu ((va danh) OR (va dinh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (do sanh)) ky nang xa hoi. hieu va dam tu ((va danh) OR (va dinh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (do sanh)) ky nang xa hoi. hieu va dam tu ((va danh) OR (va dinh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (do sanh)) ky nang xa hoi. hieu va dam tu ((va danh) OR (va dinh)) vi cua tre*.