Perhaps you should try some spelling variations:
ban thanh » ban hang
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
ban hanh » ban hang
cau tren » cu tren, dau tren, ca tren
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
van cam » van nam, van lam, van cau
vai cau » va cau, van cau, vai cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (thu sach)) ky nang xa hoi. hieu van cam xuc ((ban thanh) OR (ban hanh)) vai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (thu sach)) ky nang xa hoi. hieu van cam xuc ((ban thanh) OR (ban hanh)) vai cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (thu sach)) ky nang xa hoi. hieu van cam xuc ((ban thanh) OR (ban hanh)) vai cau tren".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (thu sach)) ky nang xa hoi. hieu van cam xuc ((ban thanh) OR (ban hanh)) vai cau tren*.