Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
cac truc » cau truc, cac tru, cac trung
hieu ve » hieu va, hieu van
su sach » vu sach
lang xa » lang ha, dang xay, lang van
so sach » so sanh, bo sach, co sach
v lang » va lang, o lang, _ lang
ve cac » va cac, vien cac
oi su » ki su, vi su

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) or (so sach)) v lang xa hoi. hieu ve cac truc ((ban hang) OR (ngan hang)) oi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) v lang xa hoi. hieu ve cac truc ((ban hang) OR (ngan hang)) oi su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sach)) v lang xa hoi. hieu ve cac truc ((ban hang) OR (ngan hang)) oi su triet".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sach)) v lang xa hoi. hieu ve cac truc ((ban hang) OR (ngan hang)) oi su triet*.