Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
cua triet » cua viet, su triet, va triet
thuc ban » thuoc ban, thuc dan, thu ban
ban hanh » ban hang
hanh vai » hanh vi, hanh va, hanh tai
ky mang » ky nang, ke mang, ky dang
may hoi » may thoi, tay hoi, mai hoi
vai cua » dai cua, hai cua, lai cua
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky mang may hoi. ((((hieu va) OR (lieu va))) or (hieu qua)) tham thuc ban hanh vai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky mang may hoi. ((((hieu va) OR (lieu va))) OR (hieu qua)) tham thuc ban hanh vai cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky mang may hoi. ((((hieu va) OR (lieu va))) or (hieu qua)) tham thuc ban hanh vai cua triet".
• Adding a wildcard symbol may retrieve word variants: tu sac ky mang may hoi. ((((hieu va) OR (lieu va))) or (hieu qua)) tham thuc ban hanh vai cua triet*.