Perhaps you should try some spelling variations:
hanh thai » nhanh thai, hinh thai, hanh tai
van hanh » van thanh, ban hanh, van anh
dua tren » dung tren
duc van » duc va, duc tan, duc manh
cua tre » cua te, cua triet, cua thep
cuu tre » cau tren, cau treo
cac duc » cac du, cao duc, cac dac
hieu ve » hieu va, hieu van
sac ky » cac ky, sai ky
ve cac » va cac, vien cac
nang o » nang co, nang ho, nang ro
tu sac » tu sach, tu cac, tu san
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 ky nang o lai. hieu ve cac duc van hanh thai ((((cua tre) or (dua tren))) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky nang o lai. hieu ve cac duc van hanh thai ((((cua tre) OR (dua tren))) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: tu sac ky nang o lai. hieu ve cac duc van hanh thai ((((cua tre) or (dua tren))) or (cuu tre))*.