Perhaps you should try some spelling variations:
cai nuoc » cap nuoc, cac nuoc, cuoi nuoc
te sach » toc sach
dao voi » da voi, dao noi, do voi
hieu ve » hieu va, hieu van
lua tre » cua tre, luy tre, dua tren
y nang » ky nang, ly nang, v nang
dao vi » dao ve, dao va, dao li
ve cai » va cai, ve cac, ve tai
o hoi » co hoi, o hoc, o hai
x hoi » xa 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: te sach y nang ((x hoi) or (o hoi)). hieu ve cai nuoc va ((dao vi) OR (dao voi)) lua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y nang ((x hoi) OR (o hoi)). hieu ve cai nuoc va ((dao vi) OR (dao voi)) lua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y nang ((x hoi) or (o hoi)). hieu ve cai nuoc va ((dao vi) OR (dao voi)) lua tre".
• Adding a wildcard symbol may retrieve word variants: te sach y nang ((x hoi) or (o hoi)). hieu ve cai nuoc va ((dao vi) OR (dao voi)) lua tre*.