Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
tu sach » thu sach, su sach, te sach
ky lang » ky dang, ky tang, tay lang
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao

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

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