Perhaps you should try some spelling variations:
nhanh hai » nhanh thai, thanh hai, nhanh ha
hanh hai » thanh hai, hang hai, hanh tai
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
ty dang » ky dang, ty hang, ty dong
xuc va » duc va, tuc va, luc va
va bac » van bac, va cac, va bai

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 ((ty dang) OR (ty xang)) xa hoi. hieu va bac xuc va ((hanh hai) or (nhanh hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ty dang) OR (ty xang)) xa hoi. hieu va bac xuc va ((hanh hai) OR (nhanh hai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ty dang) OR (ty xang)) xa hoi. hieu va bac xuc va ((hanh hai) or (nhanh hai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ((ty dang) OR (ty xang)) xa hoi. hieu va bac xuc va ((hanh hai) or (nhanh hai)) cua tre*.