Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
vat hanh » vat thanh, van hanh, va hanh
hanh dai » hanh tai, hanh dao, vanh dai
su sach » so sach
vu sach » vu bach, vu khach
hieu ve » hieu va, hieu van
v nang » va nang, vu nang, van nang
ve nam » he nam, va nam, le nam
cua te » cua tu
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (vu sach)) v nang ((x ho) or (o hoi)). hieu ve nam thuc vat hanh dai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) v nang ((x ho) OR (o hoi)). hieu ve nam thuc vat hanh dai cua te.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu sach)) v nang ((x ho) or (o hoi)). hieu ve nam thuc vat hanh dai cua te*.