Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
nang tai » hang tai, tang tai, sang tai
cam duc » cam xuc, cao duc, pham duc
hai cua » thai cua, dai cua, hoi cua
vai cua » dai cua, lai cua, bai cua
va hanh » van hanh, va thanh, va danh
so sach » so sanh, bo sach, co sach
hieu ve » hieu va
tai hoi » tai khoi, dai hoi, tai hai
y nang » ky nang, ly nang, v nang

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach y nang tai hoi. ((hieu ve) or (hieu van)) cam duc va hanh ((vai cua) OR (hai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y nang tai hoi. ((hieu ve) OR (hieu van)) cam duc va hanh ((vai cua) OR (hai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y nang tai hoi. ((hieu ve) or (hieu van)) cam duc va hanh ((vai cua) OR (hai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: so sach y nang tai hoi. ((hieu ve) or (hieu van)) cam duc va hanh ((vai cua) OR (hai cua)) tre*.