Perhaps you should try some spelling variations:
nam thue » nam thu, nam thuc, lam thue
thue van » thue va, thuc van, thuy van
van sang » van nang, van sung, van hang
sang tai » hang tai, sang tao, tang tai
tu sach » thu sach, su sach, te sach
hieu va » lieu va
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
x hoi » o hoi, x ho, 5 hoi

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 ((x hoi) or (xa hoi)). ((hieu va) OR (hieu qua)) nam thue van sang tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((x hoi) OR (xa hoi)). ((hieu va) OR (hieu qua)) nam thue van sang tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang ((x hoi) or (xa hoi)). ((hieu va) OR (hieu qua)) nam thue van sang tai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((x hoi) or (xa hoi)). ((hieu va) OR (hieu qua)) nam thue van sang tai cua tre*.