Perhaps you should try some spelling variations:
hanh thai » nhanh thai, hinh thai, hanh tai
thai cua » than cua, tai cuc, tri cua
van hanh » van thanh, ban hanh, van anh
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
dang xa » dang xay, lang xa, dang va
duc van » duc va, duc tan, duc manh
cac duc » cac du, cao duc, cac dac
dang ha » dong ha, dung ha, lang ha
ve cac » va cac, vien cac
su sai » su tai, su hai, su mai
su dai » sau dai, si dai, su tai

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sai) OR (su dai)) ky ((dang xa) or (dang ha)) hoi. hieu ve cac duc van hanh thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sai) OR (su dai)) ky ((dang xa) OR (dang ha)) hoi. hieu ve cac duc van hanh thai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sai) OR (su dai)) ky ((dang xa) or (dang ha)) hoi. hieu ve cac duc van hanh thai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sai) OR (su dai)) ky ((dang xa) or (dang ha)) hoi. hieu ve cac duc van hanh thai cua tre*.