Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
dat thanh » dao thanh, dat khanh, dang thanh
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
so sach » so sanh, bo sach, co sach
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) or (so sach)) ky nang x hoi. hieu van nam thuc ((dat thanh) or (ban thanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (so sach)) ky nang x hoi. hieu van nam thuc ((dat thanh) OR (ban thanh)) vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (so sach)) ky nang x hoi. hieu van nam thuc ((dat thanh) or (ban thanh)) vi cua tre*.