Perhaps you should try some spelling variations:
vien cac » vien bach, vien dai, vien da
tuan hoi » tan hoi, quang hoi, tuan hoan
hoi cua » hoi chuc
luc van » luoc van, luu van, duc van
vuc van » duc van, thuc van, chuc van
thu sac » thu sach, thu san, thu xac
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
ve cac » va cac
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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

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