Perhaps you should try some spelling variations:
ban thanh » ban hang
van cham » van chat, van tham, va cham
thu sach » thuat sach, thuoc sach, thu hoach
ban hanh » ban hang
hieu van » hieu va, thien van, lieu va
cham tuc » nham thuc, pham thuc, tham thuc
doi cua » dai cua, hoi cua, dong cua
tu sach » su sach, te sach, tu cach
nang xa » nang x, lang xa, nang ma
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: ((tu sach) or (thu sach)) y nang xa hoi. hieu van cham tuc ((ban thanh) OR (ban hanh)) doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) y nang xa hoi. hieu van cham tuc ((ban thanh) OR (ban hanh)) doi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) y nang xa hoi. hieu van cham tuc ((ban thanh) OR (ban hanh)) doi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) y nang xa hoi. hieu van cham tuc ((ban thanh) OR (ban hanh)) doi cua tre*.