Perhaps you should try some spelling variations:
nang tai » hang tai, tang tai, sang tai
cam thue » cam thu, lam thue, nam thue
tu sach » thu sach, su sach, te sach
tai cua » thai cua, tai cuc, tri cua
va nang » van nang, da nang, cam nang
thue va » thuc va, thuyet va, thuc vat
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va
y nang » ky nang, ly nang, v nang
5 hoi » o 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 ((5 hoi) or (xa hoi)). ((hieu va) OR (hieu qua)) cam thue va nang tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((5 hoi) OR (xa hoi)). ((hieu va) OR (hieu qua)) cam thue va nang tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang ((5 hoi) or (xa hoi)). ((hieu va) OR (hieu qua)) cam thue va nang tai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((5 hoi) or (xa hoi)). ((hieu va) OR (hieu qua)) cam thue va nang tai cua tre*.