Perhaps you should try some spelling variations:
cac thuc » cach thuc, cac thu, can thuc
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
vai cua » dai cua, hai cua, lai cua
te cua » le cua, de cua

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 ky lang xa hoi. hieu va cac thuc va hanh ((((te cua) OR (tue cua))) or (vai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky lang xa hoi. hieu va cac thuc va hanh ((((te cua) OR (tue cua))) OR (vai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky lang xa hoi. hieu va cac thuc va hanh ((((te cua) OR (tue cua))) or (vai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: so sach ky lang xa hoi. hieu va cac thuc va hanh ((((te cua) OR (tue cua))) or (vai cua)) tre*.