Perhaps you should try some spelling variations:
nhanh thai » nhanh thi, nhanh thanh, nhanh thang
hanh thai » hinh thai, hanh tai, anh thai
tu sach » thu sach, su sach, te sach
duc ban » duc tan, duc van, dua ban
cac duc » cac du, cao duc, cac dac
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
nang co » nang cao, nang doc, nang noi
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
nang o » nang ho, nang ro, nang x

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) OR (nang co)) hai. hieu ve cac duc ban ((hanh thai) or (nhanh thai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang o) OR (nang co)) hai. hieu ve cac duc ban ((hanh thai) OR (nhanh thai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang o) OR (nang co)) hai. hieu ve cac duc ban ((hanh thai) or (nhanh thai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang o) OR (nang co)) hai. hieu ve cac duc ban ((hanh thai) or (nhanh thai)) cua tre*.