Perhaps you should try some spelling variations:
vien cac » vien bach, vien dai, vien da
va hang » van hang, va lang, va hanh
va nang » van nang, da nang, cam nang
tu sach » thu sach, su sach, te sach
viec va » vien va, viec cua, viec lam
cao hoa » cao hoat, cao khoa, cau hoa
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 hoa. hieu ((viec va) or (vien cac)) tu ((va hang) OR (va nang)) va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang cao hoa. hieu ((viec va) OR (vien cac)) tu ((va hang) OR (va nang)) va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang cao hoa. hieu ((viec va) or (vien cac)) tu ((va hang) OR (va nang)) va cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang cao hoa. hieu ((viec va) or (vien cac)) tu ((va hang) OR (va nang)) va cua tre*.