Perhaps you should try some spelling variations:
cao hoat » cac hoat, co hoat, cao chat
viec cac » viec cua, viec lam, viec va
vien cac » vien bach, vien dai, vien da
tu sach » thu sach, su sach, te sach
va nang » van nang, da nang, cam nang
nang va » nang van, hang va, nang ma
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
va cua » va chua, via cua, ca cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y nang cao hoat. hieu ((viec cac) or (vien cac)) tu va nang va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang cao hoat. hieu ((viec cac) OR (vien cac)) tu va nang va cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang cao hoat. hieu ((viec cac) or (vien cac)) tu va nang va cua tre*.