Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
cam thuc » am thuc, nam thuc, cam thu
hieu va » lieu va, hieu qua
hanh di » hanh vi, hanh de, hang di
su sach » vu sach
hieu ve » hieu van
so sach » so sanh, bo sach, co sach
x hoi » xa hoi, o hoi, x ho
di su » doi su, ki su, da 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) or (so sach)) ky nang x hoi. ((hieu ve) OR (hieu va)) cam thuc van hanh di su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) ky nang x hoi. ((hieu ve) OR (hieu va)) cam thuc van hanh di su triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sach)) ky nang x hoi. ((hieu ve) OR (hieu va)) cam thuc van hanh di su triet*".