Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
ban hanh » ban hang
van hanh » van thanh, van anh, van ban
sach vu » sach va, sach tu, sach uu
su tien » su kien, su hien, tu tieng
nang ma » tang ma, sang ma, nang cao
vu nang » vuc nang, va nang, vu dang
va cao » va cac, va co, va dao
va cam » va cham, va cac, va cai
ma hoi » mai hoi, xa hoi, ma hoa
ki su » ky su

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 vu nang ma hoi. hieu ((va cam) or (va cao)) xuc ((van hanh) or (ban hanh)) ki su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach vu nang ma hoi. hieu ((va cam) OR (va cao)) xuc ((van hanh) OR (ban hanh)) ki su tien.
• Adding a wildcard symbol may retrieve word variants: thu sach vu nang ma hoi. hieu ((va cam) or (va cao)) xuc ((van hanh) or (ban hanh)) ki su tien*.