Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
cua triet » cua viet, va triet
ban thanh » ban hanh, ban hang
su triet » su viet, su tien, ve triet
dang xay » dang van, van xay
cuu ban » cuu van, cua ban, cuu san
tu sach » thu sach, su sach, te sach
cam cuu » cham cuu, cap cuu
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
va cam » va cham, va cac, va cao

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) or (dang xay)) hoi. hieu va cam cuu ban thanh tai ((cua triet) OR (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang ma) OR (dang xay)) hoi. hieu va cam cuu ban thanh tai ((cua triet) OR (su triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang ma) or (dang xay)) hoi. hieu va cam cuu ban thanh tai ((cua triet) OR (su triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang ma) or (dang xay)) hoi. hieu va cam cuu ban thanh tai ((cua triet) OR (su triet))*.