Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
dam cua » dai cua, day cua, nam cua
tu sach » thu sach, su sach, tu cach
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
te sach » toc sach
cua tre » cua te, cuu tre, cua triet
nam tu » nam thu, nam thuc

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) or (te sach)) ty nang xa hoi. hieu van nam tu ((ban thanh) or (gia thanh)) dam cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ty nang xa hoi. hieu van nam tu ((ban thanh) OR (gia thanh)) dam cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) ty nang xa hoi. hieu van nam tu ((ban thanh) or (gia thanh)) dam cua tre*.