Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
cham thuc » nham thuc, pham thuc, tham thuc
hieu van » hieu va, thien van, lieu va
hang dai » hoang dai, hang tai, hang dau
day hang » dat hang, dai hang, day nang
thuc day » thuc dan, thuc vat
su sach » so sach, vu sach
nang xa » lang xa, nang ma, mang xa
hieu ve » hieu va
sach v » sach va, sach y, sach 2

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 v ((nang xa) OR (nang x)) hoi. ((hieu ve) OR (hieu van)) cham thuc day hang dai cua triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach v ((nang xa) or (nang x)) hoi. ((hieu ve) OR (hieu van)) cham thuc day hang dai cua triet~".
• Adding a wildcard symbol may retrieve word variants: su sach v ((nang xa) or (nang x)) hoi. ((hieu ve) OR (hieu van)) cham thuc day hang dai cua triet*.