Perhaps you should try some spelling variations:
thanh vi » thanh va, thanh ve, nhanh vi
cac truc » cau truc, cac tru, cac trung
su sach » so sach, vu sach
truc va » thuc va, thuc vat, trung va
sach ty » sach y, sach tu, sach thu
su tien » su kien, su hien, tu tieng
hieu ve » hieu va, hieu van
ve cac » va cac, vien cac
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: su sach ty xang ((x hoi) OR (o hoi)). hieu ve cac truc va ((thanh vi) or (hanh vi)) su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty xang ((x hoi) OR (o hoi)). hieu ve cac truc va ((thanh vi) OR (hanh vi)) su tien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty xang ((x hoi) OR (o hoi)). hieu ve cac truc va ((thanh vi) or (hanh vi)) su tien".
• Adding a wildcard symbol may retrieve word variants: su sach ty xang ((x hoi) OR (o hoi)). hieu ve cac truc va ((thanh vi) or (hanh vi)) su tien*.