Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
vanh dai » van dai, vanh tai, lanh dao
dang xay » dang van, van xay
hanh dai » hanh tai, hanh dao, thanh dat
cac thuc » cach thuc, cac thu, can thuc
su sach » so sach, vu sach
sach va » sach xa, sach ha, sach dao
hieu ve » hieu va, hieu van
ve cac » va cac, vien cac

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: su sach va ((dang xay) OR (nang x)) hoi. hieu ve cac thuc vat ((hanh dai) OR (vanh dai)) cua triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach va ((dang xay) or (nang x)) hoi. hieu ve cac thuc vat ((hanh dai) OR (vanh dai)) cua triet~".
• Adding a wildcard symbol may retrieve word variants: su sach va ((dang xay) or (nang x)) hoi. hieu ve cac thuc vat ((hanh dai) OR (vanh dai)) cua triet*.