Perhaps you should try some spelling variations:
cac truc » cau truc, cac tru, cac trung
va thanh » gia thanh, ban thanh, va tinh
thanh vi » hanh vi, thanh va, thanh ve
so sach » so sanh, bo sach, co sach
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
truc va » thuc va, thuc vat, trung va
su tien » su kien, su hien, tu tieng
ve cac » va cac, vien cac
x hoi » xa hoi, x ho, 5 hoi
o hoi » co hoi, o hoc, o hai
vi su » va su, ve su, ki su

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ty xang ((x hoi) OR (o hoi)). hieu ve cac truc va thanh vi su tien~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ty xang ((x hoi) OR (o hoi)). hieu ve cac truc va thanh vi su tien".
• Adding a wildcard symbol may retrieve word variants: so sach ty xang ((x hoi) OR (o hoi)). hieu ve cac truc va thanh vi su tien*.