Perhaps you should try some spelling variations:
tham thuc » nham thuc, tam thuc, thai thuc
pham thuc » phap thuc, pham chuc, nham thuc
cua viet » ca viet, hoa viet, cua vat
hanh hai » thanh hai, nhanh hai, hang hai
ban hanh » ban hang
hai cua » thai cua, dai cua, hoi cua
hieu va » lieu va, hieu qua
may hoi » may thoi, tay hoi, mai hoi
sac 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) or (cac ky)) mang may hoi. hieu va ((tham thuc) OR (pham thuc)) ban hanh hai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sac ky) OR (cac ky)) mang may hoi. hieu va ((tham thuc) OR (pham thuc)) ban hanh hai cua viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sac ky) or (cac ky)) mang may hoi. hieu va ((tham thuc) OR (pham thuc)) ban hanh hai cua viet*".