Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
danh vai » danh sai, danh va, doanh van
hieu va » lieu va, hieu qua
vai cau » va cau, van cau, vai cac
va danh » va dinh, va dan, va hanh
cac xuc » cam xuc, cac nuoc, chat xuc
tu sach » thu sach, su sach, te sach
hieu ve » hieu van
mai hoi » mai khoi, dai hoi, lai hoi
ky tang » ky nang, kho tang, ky trong
ky dang » ky nang, ky danh
xuc va » duc va, tuc va, luc va

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 dang) or (ky tang)) mai hoi. ((hieu ve) OR (hieu va)) cac xuc va danh vai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky dang) OR (ky tang)) mai hoi. ((hieu ve) OR (hieu va)) cac xuc va danh vai cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky dang) or (ky tang)) mai hoi. ((hieu ve) OR (hieu va)) cac xuc va danh vai cau tren".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky dang) or (ky tang)) mai hoi. ((hieu ve) OR (hieu va)) cac xuc va danh vai cau tren*.