Perhaps you should try some spelling variations:
cam thuc » am thuc, nam thuc, cam thu
hanh dai » hanh tai, hanh dao, vanh dai
su triet » su viet, su tien, ve triet
su sach » so sach, vu sach
va nang » van nang, da nang, cam nang
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
v nang » vu nang, van nang, voi nang
ve cam » ve cham, ve cac, va cam
dai su » dai sua, dai so, dan su

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ((v nang) or (va nang)) xa hoi. hieu ve cam thuc va hanh dai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((v nang) OR (va nang)) xa hoi. hieu ve cam thuc va hanh dai su triet.
• Adding a wildcard symbol may retrieve word variants: su sach ((v nang) or (va nang)) xa hoi. hieu ve cam thuc va hanh dai su triet*.