Perhaps you should try some spelling variations:
tang mai » tang ma, tang tai, lang mai
cau thuc » cau truc, cuu thuc, cau phuc
can thuc » dan thuc, van thuc, cay thuc
ban hang » ngan hang
cua viet » ca viet, hoa viet, cua vat
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
ky tang » ky nang, ky dang, kho tang
mai hoi » mai khoi, dai hoi, lai hoi
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 tang mai hoi. lieu va ((cau thuc) OR (can thuc)) ban hang va ((cua tre) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky tang mai hoi. lieu va ((cau thuc) OR (can thuc)) ban hang va ((cua tre) OR (cua viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky tang mai hoi. lieu va ((cau thuc) OR (can thuc)) ban hang va ((cua tre) or (cua viet))".
• Adding a wildcard symbol may retrieve word variants: so sach ky tang mai hoi. lieu va ((cau thuc) OR (can thuc)) ban hang va ((cua tre) or (cua viet))*.