Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
nang cai » nang cao, nang cap, nang can
nang tai » hang tai, tang tai, sang tai
hanh dai » hanh tai, hanh dao, vanh dai
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
hieu vi » hieu voi, hieu va, hieu ve
vi tham » vi pham, va tham, vi than
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
cua te » cua tu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky ((nang cai) or (nang tai)) hoi. hieu vi tham thuc va hanh dai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky ((nang cai) OR (nang tai)) hoi. hieu vi tham thuc va hanh dai cua te.
• Adding a wildcard symbol may retrieve word variants: vu sach ky ((nang cai) or (nang tai)) hoi. hieu vi tham thuc va hanh dai cua te*.