Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
thuc day » thuc dan, thuc vat
cam thuc » am thuc, nam thuc, cam thu
hieu va » lieu va, hieu qua
hieu ve » hieu van
hanh di » hanh vi, hanh de, danh di
hang di » hang doi, hang vi, hang dien
su sach » so sach, vu sach
y nang » ky nang, ly nang, v nang

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 y nang x ho. ((hieu ve) or (hieu va)) cam thuc day ((hanh di) OR (hang di)) cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang x ho. ((hieu ve) OR (hieu va)) cam thuc day ((hanh di) OR (hang di)) cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang x ho. ((hieu ve) or (hieu va)) cam thuc day ((hanh di) OR (hang di)) cua triet".
• Adding a wildcard symbol may retrieve word variants: su sach y nang x ho. ((hieu ve) or (hieu va)) cam thuc day ((hanh di) OR (hang di)) cua triet*.