Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
cua triet » cua viet, su triet, va triet
thuc van » thuc vat, thuc dan, thuc va
van hanh » van thanh, ban hanh, van anh
hanh dai » hanh tai, hanh dao, vanh dai
sach ky » sach y, sach ty, sach kem
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
va tham » van tham, va cham, va thanh
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: thu ((sach ky) or (sac ky)) nang ma hoa. hieu va tham thuc van hanh dai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sac ky)) nang ma hoa. hieu va tham thuc van hanh dai cua triet.
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) or (sac ky)) nang ma hoa. hieu va tham thuc van hanh dai cua triet*.