Perhaps you should try some spelling variations:
ban thanh » ban hanh
ban hang » ngan hang
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
vai cua » dai cua, lai cua, bai cua
hai cua » thai cua, dai cua, hoi cua
y nang » ky nang, ly nang, v nang
ve cac » va cac, vien cac

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 y nang xa hoi. hieu ve cac du ((ban thanh) OR (ban hang)) ((vai cua) or (hai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang xa hoi. hieu ve cac du ((ban thanh) OR (ban hang)) ((vai cua) OR (hai cua)) tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang xa hoi. hieu ve cac du ((ban thanh) OR (ban hang)) ((vai cua) or (hai cua)) tre*".