Perhaps you should try some spelling variations:
sach han » sach tham, sach danh, sach nang
han nang » phan nang, van nang, ban nang
truc van » truc va, thuc van, truc ban
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
hanh ve » hanh vi, hanh va, hanh kem
cua tre » cuu tre, cua triet, dua tren
nang o » nang co, nang ho, nang ro
ve cau » ke cau, va cau, ve cac
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.

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach han nang o hoi. hieu ve cau truc van hanh ve ((cua tre) OR (cua te))~.
• Adding a wildcard symbol may retrieve word variants: su sach han nang o hoi. hieu ve cau truc van hanh ve ((cua tre) or (cua te))*.