Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
qua cam » qua cham, qua ca, qua cai
qua cac » cua cac
va hanh » va thanh, va danh, ban hanh
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet

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

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