Perhaps you should try some spelling variations:
nang mai » nang ma, nang tai, lang mai
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
mai hoi » mai khoi, dai hoi, lai hoi
xuc va » duc va, tuc va, xac va
luc va » duc va, tuc va, loc va
vi cua » vai cua, di cua
va cao » va cac, va co, va dao

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (do sanh)) ky nang mai hoi. hieu va cao ((xuc va) or (luc va)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (do sanh)) ky nang mai hoi. hieu va cao ((xuc va) OR (luc va)) hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (do sanh)) ky nang mai hoi. hieu va cao ((xuc va) or (luc va)) hanh vi cua tre*.