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