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

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