Perhaps you should try some spelling variations:
cam thuc » am thuc, nam thuc, cam thu
hieu van » hieu va, thien van, lieu va
lai cua » dai cua, lai chau, thai cua
hai cua » thai cua, dai cua, hoi cua
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
hieu ve » hieu va
nang xa » nang x, lang xa, nang ma
can ky » van ky, dan ky, ban ky
tu can » tu ban, tu cac, thu canh

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu can ky nang xa hoi. ((hieu ve) OR (hieu van)) cam thuc va hanh ((hai cua) or (lai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu can ky nang xa hoi. ((hieu ve) OR (hieu van)) cam thuc va hanh ((hai cua) OR (lai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu can ky nang xa hoi. ((hieu ve) OR (hieu van)) cam thuc va hanh ((hai cua) or (lai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: tu can ky nang xa hoi. ((hieu ve) OR (hieu van)) cam thuc va hanh ((hai cua) or (lai cua)) tre*.