Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
tham thuc » nham thuc, pham thuc, tam thuc
hanh vai » hanh vi, hanh va, hanh tai
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
nang ma » tang ma, sang ma, nang cao
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach tu, sach thu
vai cua » dai cua, hai cua, lai cua
hieu va » hieu qua
ma hoi » mai hoi, xa hoi, ma hoa

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 (sach ty)) nang ma hoi. ((hieu va) OR (lieu va)) tham thuc van hanh vai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sach ty)) nang ma hoi. ((hieu va) OR (lieu va)) tham thuc van hanh vai cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ky) or (sach ty)) nang ma hoi. ((hieu va) OR (lieu va)) tham thuc van hanh vai cua triet".
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) or (sach ty)) nang ma hoi. ((hieu va) OR (lieu va)) tham thuc van hanh vai cua triet*.