Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
vu khach » vu khac, vay khach, cua khach
vu khanh » vu thanh, van khanh, duy khanh
hieu van » hieu va, thien van, lieu va
thanh di » thanh doi, thanh de, thanh do
cau tren » cu tren, dau tren, ca tren
van bao » van ban, van dao
bao thu » bao thuc, ba thu, ban thu
thu ban » thu hang
di cau » da cau, diem cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu khach) or (vu khanh)) ky nang ((x ho) or (xa hoi)). hieu van bao thu ban thanh di cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu khach) OR (vu khanh)) ky nang ((x ho) OR (xa hoi)). hieu van bao thu ban thanh di cau tren.
• Adding a wildcard symbol may retrieve word variants: ((vu khach) or (vu khanh)) ky nang ((x ho) or (xa hoi)). hieu van bao thu ban thanh di cau tren*.