Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
su sach » so sach, vu sach
va hanh » van hanh, va thanh, ban hanh
vai cua » dai cua, hai cua, lai cua
va danh » va dinh, va dan, dia danh
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
ve nam » he nam, va nam, le nam

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 (toc sach)) ky nang xa hoi. hieu ve nam thu ((va hanh) or (va danh)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (toc sach)) ky nang xa hoi. hieu ve nam thu ((va hanh) OR (va danh)) vai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (toc sach)) ky nang xa hoi. hieu ve nam thu ((va hanh) or (va danh)) vai cua tre*.