Perhaps you should try some spelling variations:
nhanh thi » nhanh thai, nhanh thuc, nhan tai
hanh thai » nhanh thai, hinh thai, hanh tai
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
nang o » nang co, nang ho, nang ro
ve cac » va cac, vien cac
du ban » dua ban, duc ban, du bao
o hai » co hai, so hai, o lai

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang o hai. hieu ve cac du ban ((hanh thai) or (nhanh thi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang o hai. hieu ve cac du ban ((hanh thai) OR (nhanh thi)) cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang o hai. hieu ve cac du ban ((hanh thai) or (nhanh thi)) cua tre*.