Perhaps you should try some spelling variations:
ban hanh » ban hang
dang mai » dang hai, dang mau, dang bai
mai khoi » mai khoa, tai khoa, cac khoi
chat cuc » chat cua, chat xuc, chi cuc
tu sach » thu sach, su sach, te sach
ky dang » ky nang, ky danh
hieu va » hieu qua
sach ky » sac ky, sach y, sach ty
cuc ban » cua ban, cac ban, cuu ban
cua tu » cua tuc, cua su, cua te
cua cu » cua chu, cua cau, cua su

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 dang mai khoi. ((hieu va) or (lieu va)) chat cuc ban hanh vi ((cua tu) OR (cua cu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky dang mai khoi. ((hieu va) OR (lieu va)) chat cuc ban hanh vi ((cua tu) OR (cua cu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky dang mai khoi. ((hieu va) or (lieu va)) chat cuc ban hanh vi ((cua tu) OR (cua cu))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky dang mai khoi. ((hieu va) or (lieu va)) chat cuc ban hanh vi ((cua tu) OR (cua cu))*.