Perhaps you should try some spelling variations:
su triet » su viet, ve triet
thanh vi » hanh vi, thanh va, thanh ve
va thanh » gia thanh, ban thanh, va tinh
so sach » so sanh, bo sach, co sach
sach ty » sach y, sach tu, sach thu
cac toc » cac toi, cac nuoc, cac thoi
ty lang » tay lang, ty xang, ty hang
hieu ve » hieu va, hieu van
su tien » su kien, su hien, tu tieng
ve cac » va cac, vien cac
toc va » hoc va, toc ta, tuc va
lang o » lang _, tang o, lang son
o hoi » co hoi, o hoc, o hai

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 lang o hoi. hieu ve cac toc va thanh vi ((su triet) or (su tien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty lang o hoi. hieu ve cac toc va thanh vi ((su triet) OR (su tien)).
• Adding a wildcard symbol may retrieve word variants: so sach ty lang o hoi. hieu ve cac toc va thanh vi ((su triet) or (su tien))*.