Perhaps you should try some spelling variations:
thuc van » thuc vat, thuc dan, thuc va
cam thuc » am thuc, nam thuc, cam thu
cao hoi » cau hoi, co hoi, cao hoc
hieu ve » hieu van
hieu va » lieu va, hieu qua
van anh » van thanh, tuan anh, van minh
vi hoc » va hoc
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sac ky nang cao hoi. ((hieu ve) or (hieu va)) cam thuc van anh ((vi hoc) OR (li hoc)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky nang cao hoi. ((hieu ve) OR (hieu va)) cam thuc van anh ((vi hoc) OR (li hoc)) viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky nang cao hoi. ((hieu ve) or (hieu va)) cam thuc van anh ((vi hoc) OR (li hoc)) viet".
• Adding a wildcard symbol may retrieve word variants: su sac ky nang cao hoi. ((hieu ve) or (hieu va)) cam thuc van anh ((vi hoc) OR (li hoc)) viet*.