Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
ta thanh » tai thanh, va thanh, ha thanh
xa thanh » va thanh, ha thanh, gia thanh
sach ty » sach tu, sach thu, xach tay
cac tac » cac toc, cac bac, cac dac
hieu ve » hieu va, hieu van
mo phoi » mo phong
nang mo » nang meo, nang ma, nang co
ve cac » va cac, vien cac
ve su » va 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 ty) or (sach y)) nang mo phoi. hieu ve cac tac ((xa thanh) OR (ta thanh)) ve su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach y)) nang mo phoi. hieu ve cac tac ((xa thanh) OR (ta thanh)) ve su triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ty) or (sach y)) nang mo phoi. hieu ve cac tac ((xa thanh) OR (ta thanh)) ve su triet*".