Perhaps you should try some spelling variations:
thu sac » thu sach, thu san, thu xac
hieu va » lieu va, hieu qua
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
cau luc » cau truc, cau phuc
cac luc » coc luc, cac nuoc, cac cuoc
nang co » nang cao, nang doc, nang noi
hieu ve » hieu van
ca tren » cau tren, cu tren, la tren
sac ky » cac ky, sai ky
co hoi » co hoc, co loi
va ca » va cac, va cao, va cai

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

• If you are trying to use Boolean operators, they must be ALL CAPS: thu sac ky nang co hoi. ((hieu ve) OR (hieu va)) ((cac luc) OR (cau luc)) va hanh va ca tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sac ky nang co hoi. ((hieu ve) OR (hieu va)) ((cac luc) or (cau luc)) va hanh va ca tren~".
• Adding a wildcard symbol may retrieve word variants: thu sac ky nang co hoi. ((hieu ve) OR (hieu va)) ((cac luc) or (cau luc)) va hanh va ca tren*.