Perhaps you should try some spelling variations:
cac thuc » cach thuc, cac thu, can thuc
thuc gia » thuc giai, thue gia, thuc dia
thanh ve » hanh ve, thanh va, thanh vien
su triet » su viet, su tien, ve triet
so sach » so sanh, bo sach, co sach
ly nang » ky nang, ly hang, ly vang
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, v nang, may nang

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

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