Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
nang lai » nang tai, mang lai, nang cai
tinh dai » trinh dai, tinh da, tinh hai
cam thuc » am thuc, nam thuc, can thuc
cam thu » nam thu, cac thu, ca thu
cua tre » cua te, cuu tre, cua triet
va tinh » may tinh
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
lai hoi » dai hoi, lai hoa, lai roi
y nang » ky nang, ly nang, v nang

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