Perhaps you should try some spelling variations:
hieu van » thien van, lieu va
nang tai » hang tai, tang tai, sang tai
hanh vai » hanh vi, hanh va, hanh tai
so sach » so sanh, bo sach, co sach
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
cam duc » cam xuc, cao duc, pham duc
hieu va » lieu va, hieu qua
tai hoi » tai khoi, dai hoi, tai hai
cua tre » cua te, cuu tre, cua triet
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 va))) or (hieu van)) cam duc va hanh vai 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 va))) OR (hieu van)) cam duc va hanh vai 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 va))) or (hieu van)) cam duc va hanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach y nang tai hoi. ((((hieu ve) OR (hieu va))) or (hieu van)) cam duc va hanh vai cua tre*.