Perhaps you should try some spelling variations:
cam thuc » am thuc, nam thuc, cam thu
co sach » bo sach, cuon sach, hoc sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
ve cam » ve cham, ve cac, va cam
di cua » dai cua, doi cua, de cua
cua te » cua tu
x hoi » xa hoi, x ho, 5 hoi
o hoi » co hoi, o hai, o hoa
o hoc » co hoc, mo hoc, so hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: co sach ky nang ((x hoi) or (((o hoi) or (o hoc)))). hieu ve cam thuc va hanh di cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co sach ky nang ((x hoi) OR (((o hoi) OR (o hoc)))). hieu ve cam thuc va hanh di cua te.
• Adding a wildcard symbol may retrieve word variants: co sach ky nang ((x hoi) or (((o hoi) or (o hoc)))). hieu ve cam thuc va hanh di cua te*.