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
dac van » cac van, dao van, dam van
cac dac » cac dan, cac dai, cac bac
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
ty sang » ty xang, ty hang, duy sang
cua tre » cua te, cuu tre, cua triet
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: tu sach ty sang ((ma hoa) or (xa hoi)). hieu ve cac dac van ((hanh thai) OR (nhanh thai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty sang ((ma hoa) OR (xa hoi)). hieu ve cac dac van ((hanh thai) OR (nhanh thai)) cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty sang ((ma hoa) or (xa hoi)). hieu ve cac dac van ((hanh thai) OR (nhanh thai)) cua tre*".