Perhaps you should try some spelling variations:
nang xa » nang x, lang xa, nang ma
qua cac » cua cac
va hanh » van hanh, va thanh, va danh
vai cua » dai cua, hai cua, bai cua
lai cua » dai cua, hai cua, lai chau
xac ky » cac ky, sac ky
bac ky » cac ky, ban ky, sac ky
cac lo » cac lop, cac co, cac bo
lo va » lo van, lao va, ly va

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 ky) or (bac ky)) nang xa hoi. hieu qua cac lo va hanh ((vai cua) OR (lai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((xac ky) OR (bac ky)) nang xa hoi. hieu qua cac lo va hanh ((vai cua) OR (lai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((xac ky) or (bac ky)) nang xa hoi. hieu qua cac lo va hanh ((vai cua) OR (lai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: thu ((xac ky) or (bac ky)) nang xa hoi. hieu qua cac lo va hanh ((vai cua) OR (lai cua)) tre*.