Perhaps you should try some spelling variations:
hieu hien » bieu hien, dieu hien, chieu chien
thu sach » tu sach, thuat sach, thuoc sach
nam danh » nam dinh, nam dan
cac tac » cac toc, cac bac, cac dac
doi cua » dai cua, hoi cua
xa danh » va danh, dia danh, van danh
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
cac tuc » cac toc, cac tu, cac nuoc
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky nang ma hoi. hieu hien ((cac tuc) or (cac tac)) ((xa danh) OR (nam danh)) doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang ma hoi. hieu hien ((cac tuc) OR (cac tac)) ((xa danh) OR (nam danh)) doi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang ma hoi. hieu hien ((cac tuc) or (cac tac)) ((xa danh) OR (nam danh)) doi cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang ma hoi. hieu hien ((cac tuc) or (cac tac)) ((xa danh) OR (nam danh)) doi cua tre*.