Perhaps you should try some spelling variations:
hieu hien » bieu hien, dieu hien, chieu chien
hieu vien » hieu viec, thieu nien, hieu tieng
cua viet » hoa viet, cua vat, cua dieu
ban hanh » ban hang
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
ca viet » va viet, co viet, hoa viet
nang ma » tang ma, sang ma, nang cao
xu ban » xuc ban, tu ban, vu ban
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: tu sach ky nang ma hoi. ((hieu vien) OR (hieu hien)) chao xu ban hanh vi ((cua viet) or (ca viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ma hoi. ((hieu vien) OR (hieu hien)) chao xu ban hanh vi ((cua viet) OR (ca viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ma hoi. ((hieu vien) OR (hieu hien)) chao xu ban hanh vi ((cua viet) or (ca viet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ma hoi. ((hieu vien) OR (hieu hien)) chao xu ban hanh vi ((cua viet) or (ca viet))*.