Perhaps you should try some spelling variations:
ban hanh » ban hang
tru nang » tra nang, tri nang, truc nano
tu sach » thu sach, te sach, tu cach
cua tre » cuu tre, cua triet, dua tren
cuc ban » cua ban, cac ban, cuu ban
nam cuc » nam cac, nam cua, nam thuc
hieu va » lieu va, hieu qua
su sach » so sach, vu sach
va nam » van nam, ha nam, va nay
nang o » nang co, nang ho, nang ro
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: ((tu sach) or (su sach)) tru nang o hoi. hieu va nam cuc ban hanh vi ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) tru nang o hoi. hieu va nam cuc ban hanh vi ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) tru nang o hoi. hieu va nam cuc ban hanh vi ((cua tre) OR (cua te))".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) tru nang o hoi. hieu va nam cuc ban hanh vi ((cua tre) OR (cua te))*.