Perhaps you should try some spelling variations:
nhanh hai » nhanh thai, thanh hai, nhanh ha
nang tai » hang tai, sang tai, nang cao
tang tai » hang tai, dung tai, sang tao
su sach » so sach, vu sach
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
luc va » duc va, tuc va
loc va » hoc va
ve cac » va cac, vien cac

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 ky ((nang tai) OR (tang tai)) hoi. hieu ve cac ((luc va) or (loc va)) nhanh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang tai) OR (tang tai)) hoi. hieu ve cac ((luc va) OR (loc va)) nhanh hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang tai) OR (tang tai)) hoi. hieu ve cac ((luc va) or (loc va)) nhanh hai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang tai) OR (tang tai)) hoi. hieu ve cac ((luc va) or (loc va)) nhanh hai cua tre*.