Perhaps you should try some spelling variations:
hanh than » hanh han, hanh nhan, hanh phan
than cua » nhan cua, thai cua, ban cua
van hanh » van thanh, ban hanh, van anh
cua tre » cua te, cuu tre, cua triet
duc van » duc va, duc tan, duc manh
cac duc » cac du, cao duc, cac dac
hieu ve » hieu va, hieu van
ve cac » va cac, vien cac
tu sac » tu sach, tu cac, tu bac
tu san » thu san, tu ban, tu can

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sac) or (tu san)) ky nang ((o lai) OR (o lao)). hieu ve cac duc van hanh than cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sac) OR (tu san)) ky nang ((o lai) OR (o lao)). hieu ve cac duc van hanh than cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sac) or (tu san)) ky nang ((o lai) OR (o lao)). hieu ve cac duc van hanh than cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sac) or (tu san)) ky nang ((o lai) OR (o lao)). hieu ve cac duc van hanh than cua tre*.