Perhaps you should try some spelling variations:
tai thanh » thi thanh, tai chinh, ban thanh
ve triet » va trien, su triet
tai hanh » tai nhanh, thi hanh, tai anh
hanh va » hang va, hanh vi
truc va » thuc va, thuc vat, trung va
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
may hoi » may thoi, tay hoi, mai hoi
ve cac » va cac, vien cac
va ve » va de, va le, va vi

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 ((tai hanh) OR (tai thanh)) may hoi. hieu ve cac ((truc va) or (tuc xa)) hanh va ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((tai hanh) OR (tai thanh)) may hoi. hieu ve cac ((truc va) OR (tuc xa)) hanh va ve triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((tai hanh) OR (tai thanh)) may hoi. hieu ve cac ((truc va) or (tuc xa)) hanh va ve triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((tai hanh) OR (tai thanh)) may hoi. hieu ve cac ((truc va) or (tuc xa)) hanh va ve triet*.