Perhaps you should try some spelling variations:
ban hanh » ban hang
cam duc » cam xuc, cao duc, nam duoc
hanh de » hanh ve, hanh kem
hieu ve » hieu va, hieu van
tu sac » tu sach, tu cac, tu san
de cua » le cua, te cua, dieu cua
sac ky » cac ky, sai ky
so hoc » co hoc, mo hoc, so hoa
cua cu » cua chu, cua cau, cua su
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 sac ky nang ((o hoi) or (so hoc)). hieu ve ((cam duc) or (pham duc)) ban hanh de cua cu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky nang ((o hoi) OR (so hoc)). hieu ve ((cam duc) OR (pham duc)) ban hanh de cua cu.
• Adding a wildcard symbol may retrieve word variants: tu sac ky nang ((o hoi) or (so hoc)). hieu ve ((cam duc) or (pham duc)) ban hanh de cua cu*.