Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
cam thuc » am thuc, nam thuc, cam thu
nang lai » nang tai, mang lai, nang hai
tinh dai » trinh dai, tinh da, tinh hai
nang cai » nang cao, nang tai, nang cap
cua tre » cua te, cuu tre, cua triet
va tinh » may tinh
thuc va » thuc vat, thuc dan, thuc day
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
ve cam » ve cham, ve cac, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ty ((nang lai) or (nang cai)) hoi. hieu ve cam thuc va tinh dai ((cua tre) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang lai) OR (nang cai)) hoi. hieu ve cam thuc va tinh dai ((cua tre) OR (su triet)).
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang lai) or (nang cai)) hoi. hieu ve cam thuc va tinh dai ((cua tre) or (su triet))*.