Perhaps you should try some spelling variations:
cao tren » ca tren, cau tren, co tren
cau luc » cau truc, cau phuc
tai cao » thai cao, tao cao, tai sao
va dinh » van dinh, va kinh, va tinh
va hanh » van hanh, va thanh, va danh
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
hai hoi » dai hoi, hai moi, hai hai
ky dang » ky nang, ky danh
ky tang » ky nang, kho tang, ky trong
ve cau » ke cau, va cau, ve 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 tang) or (ky dang)) hai hoi. hieu ve cau luc ((va hanh) or (va dinh)) tai cao tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky tang) OR (ky dang)) hai hoi. hieu ve cau luc ((va hanh) OR (va dinh)) tai cao tren.
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky tang) or (ky dang)) hai hoi. hieu ve cau luc ((va hanh) or (va dinh)) tai cao tren*.