Perhaps you should try some spelling variations:
thau xay » thuat xay, tu xay, phan xay
va triet » va trien, ve triet, cua triet
danh vai » danh sai, danh va, doanh van
va danh » va dinh, va dan, va hanh
hieu va » lieu va, hieu qua
cac lo » cac lop, cac co, cac bo
nang o » nang co, nang ho, nang ro
lo va » lo van, lao va, ly va
o hoi » co hoi, o hoc, o hai
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu xac) or (thau xay)) ky nang o hoi. hieu va cac lo va danh vai ((va triet) OR (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu xac) OR (thau xay)) ky nang o hoi. hieu va cac lo va danh vai ((va triet) OR (va thiet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu xac) or (thau xay)) ky nang o hoi. hieu va cac lo va danh vai ((va triet) OR (va thiet))".
• Adding a wildcard symbol may retrieve word variants: ((thu xac) or (thau xay)) ky nang o hoi. hieu va cac lo va danh vai ((va triet) OR (va thiet))*.