Perhaps you should try some spelling variations:
cam thuc » am thuc, nam thuc, can thuc
hanh vai » hanh vi, hanh va, hanh tai
van nang » van quang, van ban, van dong
so sanh » do sanh
va hanh » van hanh, va thanh, va danh
cam thu » nam thu, cac thu, ca thu
hieu ve » hieu va, hieu van
dai hoi » dai hoc, dai hai, dai moi
va nang » da nang, cam nang, kha nang
vai cua » dai cua, hai cua, lai cua

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

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