Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
doc sach » hoc sach, nuoc sach, dac sac
hieu van » hieu va, thien van, lieu va
van nang » van quang, van ban, van dong
van hanh » van thanh, ban hanh, van anh
nang xa » nang x, lang xa, nang ma
va hanh » va thanh, va danh, ban hanh
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang

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