Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
hanh tri » thanh tri, hanh tai, hanh trinh
van hanh » van thanh, ban hanh, van anh
vien cac » vien bach, vien dai, vien da
cua tre » cua te, cuu tre, cua triet
duc van » duc va, duc tan, duc manh
cac duc » cac du, cao duc, cac dac
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 vien cac duc van hanh tri 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 vien cac duc van hanh tri cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sac) or (tu san)) ky nang ((o lai) or (o lao)). hieu vien cac duc van hanh tri cua tre*.