Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien cac » vien bach, vien dai, vien da
thai cua » than cua, tai cuc, tri cua
van quan » van ban
van xuan » van tuan, van xuat, van huan
cac xuc » cam xuc, cac nuoc, chat xuc
cua tre » cua te, cuu tre, cua triet
nang o » nang co, nang ho, nang ro
tu san » thu san, tu ban, tu can
tu sac » tu sach, tu cac, tu bac
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 san)) ky nang o lai. hieu vien cac xuc ((van xuan) OR (van quan)) thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sac) OR (tu san)) ky nang o lai. hieu vien cac xuc ((van xuan) OR (van quan)) thai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sac) or (tu san)) ky nang o lai. hieu vien cac xuc ((van xuan) OR (van quan)) thai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sac) or (tu san)) ky nang o lai. hieu vien cac xuc ((van xuan) OR (van quan)) thai cua tre*.