Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
ban hang » ngan hang
chat soc » cham soc, chat hoc, chat doc
hieu va » hieu qua
va danh » va dinh, va dan, va hanh
cam ky » cao ky, cac ky
di dau » doi dau, bi dau, di du
tu cam » tu cham, tu cac, tu nam
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu cam ky nang x hoi. ((hieu va) OR (lieu va)) chat soc ((ban hang) or (va danh)) di dau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cam ky nang x hoi. ((hieu va) OR (lieu va)) chat soc ((ban hang) OR (va danh)) di dau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cam ky nang x hoi. ((hieu va) OR (lieu va)) chat soc ((ban hang) or (va danh)) di dau tren".
• Adding a wildcard symbol may retrieve word variants: tu cam ky nang x hoi. ((hieu va) OR (lieu va)) chat soc ((ban hang) or (va danh)) di dau tren*.