Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
ban hanh » ban hang
thuc ban » thuoc ban, thuc dan, thu ban
lai cua » dai cua, hai cua, lai chau
vai cua » dai cua, hai cua, bai cua
va tham » van tham, va cham, va thanh
hieu va » lieu va, hieu qua
may hoi » may thoi, tay hoi, mai hoi
ky mang » ke mang, ky dang, ky tang
tu sac » tu sach, tu cac, tu san

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) OR (ky nang)) may hoi. hieu va tham thuc ban hanh ((vai cua) or (lai cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ((ky mang) OR (ky nang)) may hoi. hieu va tham thuc ban hanh ((vai cua) OR (lai cua)) triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ((ky mang) OR (ky nang)) may hoi. hieu va tham thuc ban hanh ((vai cua) or (lai cua)) triet*".