Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
hieu van » thien van, lieu va, hieu ve
cam thuc » am thuc, nam thuc, cam thu
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
cua tre » cua te, cuu tre, cua triet
vu sach » vu bach, su sach, vu khach
v nang » va nang, vu nang, van nang
sach v » sach va, sach y, sach 2

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach v nang xa hoi. ((hieu van) or (hieu va)) cam thuc va hanh di ((cua tre) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach v nang xa hoi. ((hieu van) OR (hieu va)) cam thuc va hanh di ((cua tre) OR (su triet)).
• Adding a wildcard symbol may retrieve word variants: vu sach v nang xa hoi. ((hieu van) or (hieu va)) cam thuc va hanh di ((cua tre) or (su triet))*.