Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
tay thoi » tay hoi, tay thai, gay thoi
thuc ban » thuoc ban, thuc dan, thu ban
ban hang » ngan hang
hang vai » hang va, hang tai, hang hai
cua viet » ca viet, hoa viet, cua dieu
ky mang » ky nang, ke mang, ky dang
may hoi » may thoi, tay hoi, mai hoi
hieu va » lieu va, hieu qua
va tham » van tham, va cham, va thanh

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu cac ky mang ((may hoi) or (tay thoi)). hieu va tham thuc ban hang vai ((cua viet) or (cua vat))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac ky mang ((may hoi) OR (tay thoi)). hieu va tham thuc ban hang vai ((cua viet) OR (cua vat)).
• Adding a wildcard symbol may retrieve word variants: tu cac ky mang ((may hoi) or (tay thoi)). hieu va tham thuc ban hang vai ((cua viet) or (cua vat))*.