Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
cham duc » pham duc, cham soc, pham duy
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
nang xa » nang x, lang xa, nang ma
duc van » duc va, duc tan, duc manh
sac ky » cac ky, sai ky
vi su » va su, ki su, oi su
ve su » va su

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) or (sach y)) nang xa hoi. hieu van cham duc van hanh ((vi su) OR (ve su)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sac ky) OR (sach y)) nang xa hoi. hieu van cham duc van hanh ((vi su) OR (ve su)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sac ky) or (sach y)) nang xa hoi. hieu van cham duc van hanh ((vi su) OR (ve su)) triet".
• Adding a wildcard symbol may retrieve word variants: tu ((sac ky) or (sach y)) nang xa hoi. hieu van cham duc van hanh ((vi su) OR (ve su)) triet*.