Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
thanh vi » hanh vi, thanh va, thanh ve
xa thanh » va thanh, ha thanh, ta thanh
cac bac » cac bai, cac ban, cac cach
cac tac » cac toc, cac dac, cac tai
hieu ve » hieu va, hieu van
tu sach » thu sach, te sach, tu cach
lang co » lang o, nang co, tang co
ty lang » tay lang, ty xang, ty hang
su sach » so sach, vu sach
co hai » co dai, co hoi, 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: ((tu sach) or (su sach)) ty lang co hai. hieu ve ((cac tac) OR (cac bac)) xa thanh vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ty lang co hai. hieu ve ((cac tac) OR (cac bac)) xa thanh vi su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) ty lang co hai. hieu ve ((cac tac) OR (cac bac)) xa thanh vi su triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ty lang co hai. hieu ve ((cac tac) OR (cac bac)) xa thanh vi su triet*.