Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
sach tay » xach tay, sach hay, sach nay
tay lang » tai lang, tay tang, tay quang
xa nong » xa dong, xuat nong, may nong
xa nang » da nang, va nang, ca nang
cac toc » cac toi, cac nuoc, cac thoi
te sach » toc sach
hieu ve » hieu va, hieu van
cac tuc » cac tu, cac tac, cac nuoc
lang xa » lang ha, dang xay, lang van
ho su » hoc su, hoa su, ho so

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

• If you are trying to use Boolean operators, they must be ALL CAPS: te sach tay lang xa hoi. hieu ve ((cac tuc) OR (cac toc)) ((xa nang) OR (xa nong)) ho su triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach tay lang xa hoi. hieu ve ((cac tuc) or (cac toc)) ((xa nang) OR (xa nong)) ho su triet~".
• Adding a wildcard symbol may retrieve word variants: te sach tay lang xa hoi. hieu ve ((cac tuc) or (cac toc)) ((xa nang) OR (xa nong)) ho su triet*.