Perhaps you should try some spelling variations:
van danh » van doanh, van anh, van hanh
tu sach » thu sach, su sach, te sach
ty nang » ty xang, ty hang, ly nang
hieu va » lieu va, hieu qua
cac lo » cac lop, cac co, cac bo
lo van » le van, vo van, so van
va cua » va chua, via cua, ma cua
ca cua » co cua

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 ((ty nang) OR (ky nang)) cau hoi. hieu va cac lo van danh ((va cua) or (ca cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ky nang)) cau hoi. hieu va cac lo van danh ((va cua) OR (ca cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty nang) OR (ky nang)) cau hoi. hieu va cac lo van danh ((va cua) or (ca cua)) triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) OR (ky nang)) cau hoi. hieu va cac lo van danh ((va cua) or (ca cua)) triet*.