Perhaps you should try some spelling variations:
hanh tri » thanh tri, hanh tai, hanh trinh
ban hanh » ban hang
vien cac » vien bach, vien dai, vien da
cua tre » cua te, cuu tre, cua triet
duc ban » duc tan, duc van, dua ban
tu sac » tu sach, tu cac, tu san
nang o » nang co, nang ho, nang ro
tu ban » thu ban, te ban
ve cac » va cac
o lai » o lao

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