Perhaps you should try some spelling variations:
chat triet » chet triet, phat trien, chat thien
thanh lay » thanh lap, thanh tay, thanh lam
thanh ly » thanh ky, thanh le, khanh ly
sach ky » sach y, sach ty, sach kem
tang ha » lang ha, tang ma, trung ha
hieu ve » hieu va, hieu van
ha hoi » hoa hoi, ha noi, xa hoi
ve cac » va cac, vien cac
sac ky » cac ky, sai ky
du va » dau va, tu va, su va

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 ky) or (sac ky)) tang ha hoi. hieu ve cac du va ((thanh ly) OR (thanh lay)) chat triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sac ky)) tang ha hoi. hieu ve cac du va ((thanh ly) OR (thanh lay)) chat triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) or (sac ky)) tang ha hoi. hieu ve cac du va ((thanh ly) OR (thanh lay)) chat triet".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sac ky)) tang ha hoi. hieu ve cac du va ((thanh ly) OR (thanh lay)) chat triet*.