Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
hieu sau » hieu su, hieu suat, tieu su
sau pham » san pham, su pham, cau pham
ban hanh » ban hang
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
van anh » tuan anh, van minh
da su » dan su, dat su, va 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 nang xa hoi. hieu sau pham duc ((((van thanh) or (ban hanh))) or (van anh)) da su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu sau pham duc ((((van thanh) OR (ban hanh))) OR (van anh)) da su triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. hieu sau pham duc ((((van thanh) or (ban hanh))) or (van anh)) da su triet*.