Perhaps you should try some spelling variations:
bach duoc » bach tuoc, sach duoc, ban duoc
hieu vien » hieu hien, hieu viec, thieu nien
thanh va » thanh van, hanh va, thanh ha
thanh vi » hanh vi, thanh ve, nhanh vi
duoc gia » duoc giao, quoc gia, duc gia
tu sach » thu sach, su sach, te sach
ty nang » ky nang, ty xang, ty hang
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet
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: tu sach ty nang ((x hoi) OR (o hoi)). hieu vien bach duoc gia ((thanh vi) or (thanh va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ((x hoi) OR (o hoi)). hieu vien bach duoc gia ((thanh vi) OR (thanh va)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang ((x hoi) OR (o hoi)). hieu vien bach duoc gia ((thanh vi) or (thanh va)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ((x hoi) OR (o hoi)). hieu vien bach duoc gia ((thanh vi) or (thanh va)) cua tre*.