Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
va thanh » gia thanh, ban thanh, va tinh
ban hanh » ban hang
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
cac duc » cac du, cao duc, cac dac
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky nang xa hoi. hieu ve ((cac duc) or (cac dan)) ((ban hanh) or (va thanh)) di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang xa hoi. hieu ve ((cac duc) OR (cac dan)) ((ban hanh) OR (va thanh)) di cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang xa hoi. hieu ve ((cac duc) or (cac dan)) ((ban hanh) or (va thanh)) di cua tre*.