Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
cam thuc » am thuc, nam thuc, cam thu
hanh de » hanh ve, hanh kem
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
de cua » le cua, te cua, dieu cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach v ((nang xa) or (nang x)) hoi. ((hieu ve) OR (hieu van)) cam thuc van hanh de cua triet~.
• 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)) cam thuc van hanh de 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)) cam thuc van hanh de cua triet".
• Adding a wildcard symbol may retrieve word variants: su sach v ((nang xa) or (nang x)) hoi. ((hieu ve) OR (hieu van)) cam thuc van hanh de cua triet*.