Perhaps you should try some spelling variations:
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
su triet » su viet, su tien, ve triet
nang ma » tang ma, sang ma, nang cao
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach tu, sach thu
hieu va » hieu qua
ma hoi » mai hoi, xa hoi, ma hoa
vai su » va su, van su, lai su

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 su 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 su 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 su triet*.