Perhaps you should try some spelling variations:
han nang » phan nang, van nang, ban nang
van hanh » van thanh, ban hanh, van anh
sach han » sach tham, sach danh, sach nang
truc van » truc va, thuc van, truc ban
su sach » so sach, vu sach
cua tre » cuu tre, cua triet, dua tren
hanh de » hanh ve, hanh kem
cua te » cua tu
ve cac » va cac, vien cac
ve cau » ke cau, va cau, le cau
nang o » nang co, nang ho, nang ro
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) OR (ve cac)) truc van hanh de ((cua tre) OR (cua te))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach han nang o hoi. hieu ((ve cau) OR (ve cac)) truc van hanh de ((cua tre) or (cua te))~".
• Adding a wildcard symbol may retrieve word variants: su sach han nang o hoi. hieu ((ve cau) OR (ve cac)) truc van hanh de ((cua tre) or (cua te))*.