Perhaps you should try some spelling variations:
cau thuc » cau truc, cuu thuc, can thuc
danh vai » danh sai, danh va, doanh van
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
hieu va » lieu va
thuc va » thuc vat, thuc dan, thuc day
va danh » va dinh, va dan, va hanh
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet

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 dang xa hoi. ((hieu va) OR (hieu qua)) cau thuc va danh vai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky dang xa hoi. ((hieu va) OR (hieu qua)) cau thuc va danh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach ky dang xa hoi. ((hieu va) OR (hieu qua)) cau thuc va danh vai cua tre*.