Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh vai » thanh hai, thanh van, thanh tai
nang mai » nang ma, nang tai, lang mai
hieu van » hieu va, thien van, hieu ve
cau tren » cu tren, dau tren, ca tren
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
mai hoi » mai khoi, dai hoi, lai hoi
cay lua » vay luan
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: tu sach ky nang mai hoi. ((hieu van) OR (lieu va)) ((cay lua) or (chay dua)) ban thanh vai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang mai hoi. ((hieu van) OR (lieu va)) ((cay lua) OR (chay dua)) ban thanh vai cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang mai hoi. ((hieu van) OR (lieu va)) ((cay lua) or (chay dua)) ban thanh vai cau tren".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang mai hoi. ((hieu van) OR (lieu va)) ((cay lua) or (chay dua)) ban thanh vai cau tren*.