Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
tham thuc » nham thuc, pham thuc, tam thuc
hieu van » hieu va, thien van, lieu va
hang dau » hang va, hang tai
hieu ve » hieu va
thuc va » thuc vat, thuc dan, thuc day
va hang » van hang, va nang, va lang
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, dua tren
te sach » toc sach
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach y nang ma hoi. ((hieu ve) OR (hieu van)) tham thuc va hang dau ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y nang ma hoi. ((hieu ve) OR (hieu van)) tham thuc va hang dau ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y nang ma hoi. ((hieu ve) OR (hieu van)) tham thuc va hang dau ((cua tre) or (cua triet))".
• Adding a wildcard symbol may retrieve word variants: te sach y nang ma hoi. ((hieu ve) OR (hieu van)) tham thuc va hang dau ((cua tre) or (cua triet))*.