Perhaps you should try some spelling variations:
cam thuc » am thuc, nam thuc, cam thu
thuc van » thuc vat, thuc dan, thuc va
van hanh » van thanh, ban hanh, van anh
tuc dan » thuc dan, thuc day, tung dan
hieu ve » hieu va, hieu van
hai cua » thai cua, dai cua, hoi cua
tu dan » tu ban, cu dan, tu can
ve cam » ve cham, ve cac, va cam
x hoi » xa hoi, o hoi, x ho

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

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