Perhaps you should try some spelling variations:
lang van » dang van, tang van, hoang van
va triet » va trien, ve triet, cua triet
tham luc » than luc, tham nuoc, tham thuc
hanh tai » thanh tai, hang tai, han tai
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
lang xa » lang ha, dang xay
va tham » van tham, va cham, va thanh
te sac » te sach, te cac, te san
luc va » duc va, tuc va, loc va
sac ky » cac ky, sai ky
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: te sac ky ((lang xa) OR (lang van)) hoi. hieu va tham luc va hanh tai ((va triet) or (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky ((lang xa) OR (lang van)) hoi. hieu va tham luc va hanh tai ((va triet) OR (va thiet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ky ((lang xa) OR (lang van)) hoi. hieu va tham luc va hanh tai ((va triet) or (va thiet))".
• Adding a wildcard symbol may retrieve word variants: te sac ky ((lang xa) OR (lang van)) hoi. hieu va tham luc va hanh tai ((va triet) or (va thiet))*.