Perhaps you should try some spelling variations:
hanh vai » hanh va, hanh tai, hanh van
so sach » so sanh, bo sach, co sach
cam duc » cam xuc, cao duc, pham duc
hieu va » lieu va, hieu qua
lang xa » dang xay, lang van
lang ha » long ha
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao

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 ((lang xa) or (lang ha)) hoi. hieu va cam duc va ((hanh vai) OR (hanh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y ((lang xa) OR (lang ha)) hoi. hieu va cam duc va ((hanh vai) OR (hanh vi)) cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y ((lang xa) or (lang ha)) hoi. hieu va cam duc va ((hanh vai) OR (hanh vi)) cua tre*".