Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
lang tai » lang thai, hang tai, tang tai
sach ky » sac ky, sach y, sach ty
tai cua » thai cua, tai cuc, tri cua
va lang » va nang, hoa lang
cac toc » cac nuoc, cac thoi
cac toi » cac thoi
hieu ve » hieu van
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
cua te » cua tu

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 sach ky nang ma hoa. ((hieu ve) OR (hieu va)) ((cac toi) OR (cac toc)) va lang tai cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang ma hoa. ((hieu ve) OR (hieu va)) ((cac toi) or (cac toc)) va lang tai cua te~".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang ma hoa. ((hieu ve) OR (hieu va)) ((cac toi) or (cac toc)) va lang tai cua te*.