Perhaps you should try some spelling variations:
cac thuc » cach thuc, cac thu, can thuc
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
y nang » ly nang, v nang, may nang
ve cac » va cac, vien cac
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ((y nang) or (ky nang)) x hoi. hieu ve cac thuc va hanh vi ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((y nang) OR (ky nang)) x hoi. hieu ve cac thuc va hanh vi ((cua tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: su sach ((y nang) or (ky nang)) x hoi. hieu ve cac thuc va hanh vi ((cua tre) or (cuu tre))*.